I'm seeing problems with avast.setup as well. It seems that despite the below normal thread priority it will push itself infront and cause a system slowdown when the CPU is under heavy load.
I'm regularly getting decreased performance when playing eve-online, which will continue to get worse and worse untill I exit eve and let avast.setup finish.
22:59:24.000 1209333564 system Memory: 26% load. Phys:1531088/2096624K free, Page:2360124/2991524K free, Virt:2069400/2097024K free
27.04.2008 22:59:24.000 1209333564 system Computer WinName: (Removed)
27.04.2008 22:59:24.000 1209333564 system Windows Net User: SYSTEM
27.04.2008 22:59:24.000 1209333564 general Cmdline: /refresh /noreboot /updatevps /verysilent /limitcpu
27.04.2008 22:59:24.000 1209333564 general Operation set to INST_OP_UPDATE_INSTALL_PACKAGES
27.04.2008 22:59:24.000 1209333564 general Old version: 491 (1169)
27.04.2008 22:59:24.000 1209333564 system Using temp: C:\WINDOWS\TEMP\_av_proI.tm~a03616 (4698M free)
27.04.2008 22:59:24.000 1209333564 general SGW32P::CheckIfInstalled set m_bAlreadyInstalled to 1
27.04.2008 22:59:24.000 1209333564 system Installed in: C:\Program Files\Alwil Software\Avast4 (4698M free)
27.04.2008 22:59:24.000 1209333564 internet SYNCER: Type: use IE settings
27.04.2008 22:59:24.000 1209333564 internet SYNCER: Auth: another authentication, use WinInet
27.04.2008 22:59:24.000 1209333564 package Part prg_av_pro-491 is installed
27.04.2008 22:59:24.000 1209333564 package Part vps-8042701 is installed
27.04.2008 22:59:24.000 1209333564 package Part news-4b is installed
27.04.2008 22:59:24.000 1209333564 package Part setup_av_pro-491 is installed
27.04.2008 22:59:24.000 1209333564 package Part jrog-38 is installed
27.04.2008 22:59:24.000 1209333564 general Old version: 491 (1169)
27.04.2008 22:59:25.000 1209333565 file SetExistingFilesBitmap: 1054->154->154
27.04.2008 22:59:25.000 1209333565 general GUID: b7c8d475-6735-4c8c-bd2d-707cfb81cda3
27.04.2008 22:59:25.000 1209333565 general Entering:UpdateInstallPackages
27.04.2008 22:59:25.000 1209333565 package LoadProductVpu: C:\Program Files\Alwil Software\Avast4\Setup\prod-av_pro.vpu
27.04.2008 22:59:25.000 1209333565 package LoadPartInfo: jrog = jrog-38 returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartInfo: news = news-4b returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartInfo: program = prg_av_pro-491 returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartInfo: setup = setup_av_pro-491 returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartInfo: vps = vps-8042701 returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadProductVpu: C:\Program Files\Alwil Software\Avast4\Setup\prod-av_pro.vpu ended with 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartVpu: Loading 'part-prg_av_pro-491.vpu' returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartVpu: Loading 'part-vps-8042701.vpu' returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartVpu: Loading 'part-news-4b.vpu' returned 00000000
27.04.2008 22:59:25.000 1209333565 package LoadPartVpu: Loading 'part-setup_av_pro-491.vpu' returned 00000000
27.04.2008 22:59:25.000 1209333565 package WARN:LoadPartVpu ended on no pInfo
27.04.2008 22:59:25.000 1209333565 package LoadPartVpu: Loading 'part-jrog-38.vpu' returned 00000000
27.04.2008 22:59:25.000 1209333565 package FilterOutExistingFiles: 154 & 154 = 0
27.04.2008 22:59:25.000 1209333565 package FilterOutExistingFiles: 154 & 154 = 0
27.04.2008 22:59:25.000 1209333565 package IsFullOkay: vps-8042700.vpu - is okay
27.04.2008 22:59:25.000 1209333565 package IsFullOkay: vpsm-8042701.vpu - is okay
27.04.2008 22:59:25.000 1209333565 package ArePartsInstallable: 1
27.04.2008 22:59:46.000 1209333586 package vps: updated [8042701]
27.04.2008 22:59:46.000 1209333586 file Fix security on: C:\Program Files\Alwil Software\Avast4\*.*
27.04.2008 22:59:47.000 1209333587 file Fix security on: C:\Program Files\Alwil Software\Avast4\ENGLISH\*.*
27.04.2008 22:59:47.000 1209333587 file Fix security on: C:\Program Files\Alwil Software\Avast4\ENGLISH\HELP\*.*
27.04.2008 22:59:47.000 1209333587 file Fix security on: C:\Program Files\Alwil Software\Avast4\ENGLISH\HtmlData\*.*
27.04.2008 22:59:47.000 1209333587 file Fix security on: C:\Program Files\Alwil Software\Avast4\images\*.*
27.04.2008 22:59:47.000 1209333587 package Transferred: files 0, bytes 0, time 0 ms
27.04.2008 22:59:47.000 1209333587 package Retries: total 0, files 0, servers 0
27.04.2008 22:59:47.000 1209333587 file NeedReboot=false
27.04.2008 22:59:47.000 1209333587 general Return code: 0x20000000 [Something done]
27.04.2008 22:59:47.000 1209333587 general Stopped: 27.04.2008, 22:59:47
27.04.2008 22:59:50.000 1209333590 general Started: 27.04.2008, 22:59:50
27.04.2008 22:59:50.000 1209333590 general Running setup_av_pro-491 (1169)
27.04.2008 22:59:50.000 1209333590 system Operating system: WindowsXP ver 5.1, build 2600, sp 2.0 [Service Pack 2]
27.04.2008 22:59:50.000 1209333590 system Memory: 27% load. Phys:1512704/2096624K free, Page:2359624/2991524K free, Virt:2069400/2097024K free
27.04.2008 22:59:50.000 1209333590 system Computer WinName: (Removed)
27.04.2008 22:59:50.000 1209333590 system Windows Net User: SYSTEM
27.04.2008 22:59:50.000 1209333590 general Cmdline: /verysilent /noreboot /stopstat "C:\WINDOWS\TEMP\aswUpdSum.ini"
27.04.2008 22:59:50.000 1209333590 general Operation set to INST_OP_STOP_STAT
27.04.2008 22:59:50.000 1209333590 general Old version: 491 (1169)
27.04.2008 22:59:50.000 1209333590 system Using temp: C:\WINDOWS\TEMP\_av_proI.tm~a03532 (4698M free)
27.04.2008 22:59:50.000 1209333590 general SGW32P::CheckIfInstalled set m_bAlreadyInstalled to 1
27.04.2008 22:59:50.000 1209333590 system Installed in: C:\Program Files\Alwil Software\Avast4 (4698M free)
27.04.2008 22:59:50.000 1209333590 internet SYNCER: Type: use IE settings
27.04.2008 22:59:50.000 1209333590 internet SYNCER: Auth: another authentication, use WinInet
27.04.2008 22:59:50.000 1209333590 package Part prg_av_pro-491 is installed
27.04.2008 22:59:50.000 1209333590 package Part vps-8042701 is installed
27.04.2008 22:59:50.000 1209333590 package Part news-4b is installed
27.04.2008 22:59:50.000 1209333590 package Part setup_av_pro-491 is installed
27.04.2008 22:59:50.000 1209333590 package Part jrog-38 is installed
27.04.2008 22:59:50.000 1209333590 general Old version: 491 (1169)
27.04.2008 22:59:50.000 1209333590 package Transferred: files 0, bytes 0, time 0 ms
27.04.2008 22:59:50.000 1209333590 package Retries: total 0, files 0, servers 0
27.04.2008 22:59:50.000 1209333590 file NeedReboot=false
27.04.2008 22:59:50.000 1209333590 general Return code: 0x20000001 [Nothing done]
27.04.2008 22:59:50.000 1209333590 general Stopped: 27.04.2008, 22:59:50