I am having the same exact issue. I was fine until I did an auto-update to 4.8 and now the auto-update feature doe snot work at all. I have my proxy settings set up and previous versions used to be just fine.
09.04.2008 20:59:56 general: Started: 09.04.2008, 20:59:56
09.04.2008 20:59:56 general: Running setup_av_pro-491 (1169)
09.04.2008 20:59:56 system: Operating system: Windows2003 ver 5.2, build 3790, sp 2.0 [Service Pack 2] AMD64
09.04.2008 20:59:56 system: Memory: 23% load. Phys:3211208/4192936K free, Page:4194303/4194303K free, Virt:2042392/2097024K free
09.04.2008 20:59:56 system: Computer WinName: CASSICKR
09.04.2008 20:59:56 system: Windows Net User: ENTERPROCITY\rcassick
09.04.2008 20:59:56 general: Cmdline: /downloadpkgs /noreboot /updatevps /silent /progress
09.04.2008 20:59:56 general: DldSrc set to inet
09.04.2008 20:59:56 general: Operation set to INST_OP_UPDATE_GET_PACKAGES
09.04.2008 20:59:56 general: Old version: 44a (1098)
09.04.2008 20:59:56 system: Using temp: C:\DOCUME~1\RCASSI~1.ENT\LOCALS~1\Temp\_av_proI.tm~a01604 (287269M free)
09.04.2008 20:59:56 general: SGW32P::CheckIfInstalled set m_bAlreadyInstalled to 1
09.04.2008 20:59:56 internet: SYNCER: Agent=Syncer/4.80 (av_pro-1169;p)
09.04.2008 20:59:56 system: Computer DnsName: cassickr.Enterprocity.local
09.04.2008 20:59:56 system: Computer Ip Addr: 10.0.0.51
09.04.2008 20:59:56 system: Installed in: C:\Program Files\Alwil Software\Avast4 (287269M free)
09.04.2008 20:59:56 internet: SYNCER: Proxy enter01:8080
09.04.2008 20:59:56 internet: SYNCER: Type: standard HTTP proxy (rfc2616,2617)
09.04.2008 20:59:56 internet: SYNCER: Auth: no authentication
09.04.2008 20:59:56 package: Part prg_av_pro-491 is installed
09.04.2008 20:59:56 package: Part vps-8032900 is installed
09.04.2008 20:59:56 package: Part news-4b is installed
09.04.2008 20:59:56 package: Part setup_av_pro-491 is installed
09.04.2008 20:59:56 package: Part jrog-33 is installed
09.04.2008 20:59:56 general: Old version: 44a (1098)
09.04.2008 20:59:56 file: SetExistingFilesBitmap: 1054->144->55
09.04.2008 20:59:56 general: GUID: 053be840-bf61-48aa-ad23-a4094e27f094
09.04.2008 20:59:57 general: Server definition(s) loaded for 'main': 180 (maintenance:0)
09.04.2008 20:59:57 general: SelectCurrent: selected server 'Download924 AVAST Server' from 'main'
09.04.2008 20:59:57 package: GetPackages - set proxy for inet
09.04.2008 20:59:57 internet: SYNCER: Proxy enter01:8080
09.04.2008 20:59:57 internet: SYNCER: Type: standard HTTP proxy (rfc2616,2617)
09.04.2008 20:59:57 internet: SYNCER: Auth: no authentication
09.04.2008 20:59:57 internet: SYNCER: Proxy l/p: enterprocity\administrator/***
09.04.2008 20:59:57 general: Entered SetupProcessPro::Do( INST_OP_UPDATE_GET_PACKAGES )
09.04.2008 20:59:57 general: Entered SetupProcessWin32Avast::Do( INST_OP_UPDATE_GET_PACKAGES )
09.04.2008 20:59:57 general: Entered SetupProcessWin32::Do( INST_OP_UPDATE_GET_PACKAGES )
09.04.2008 20:59:57 general: Entered SetupProcess::Do( INST_OP_UPDATE_GET_PACKAGES )
09.04.2008 20:59:57 general: progress thread start
09.04.2008 20:59:57 internet: SYNCER: Agent=Syncer/4.80 (av_pro-1169;f)
09.04.2008 20:59:57 internet: Using NTLM
09.04.2008 20:59:57 internet: INTERNET_PER_CONN_AUTODISCOVERY_FLAGS=5
09.04.2008 20:59:57 internet: INTERNET_PER_CONN_FLAGS=15
09.04.2008 20:59:57 internet: ERROR:HttpGetWininet, catch returned 0x00002F00
09.04.2008 20:59:57 internet: Using NTLM
09.04.2008 20:59:57 internet: INTERNET_PER_CONN_AUTODISCOVERY_FLAGS=5
09.04.2008 20:59:57 internet: INTERNET_PER_CONN_FLAGS=15
09.04.2008 20:59:57 internet: ERROR:HttpGetWininet, catch returned 0x00002F00
09.04.2008 20:59:57 general: InvalidateCurrent: invalidated server 'Download924 AVAST Server' from 'main'
09.04.2008 20:59:57 general: SelectCurrent: selected server 'Download93 AVAST Server' from 'main'
09.04.2008 20:59:57 package: GetPackages - set proxy for inet
09.04.2008 20:59:57 internet: SYNCER: Proxy enter01:8080
09.04.2008 20:59:57 internet: SYNCER: Type: standard HTTP proxy (rfc2616,2617)
09.04.2008 20:59:57 internet: SYNCER: Auth: no authentication
09.04.2008 20:59:57 internet: SYNCER: Proxy l/p: enterprocity\administrator/***
09.04.2008 20:59:57 internet: while trying to get file 'servers.def.vpu', error 0x20000004 has occured, try 1
. . .
09.04.2008 21:00:30 internet: while trying to get file 'servers.def', error 0x20000004 has occured, try 9
09.04.2008 21:00:32 internet: Using NTLM
09.04.2008 21:00:32 internet: INTERNET_PER_CONN_AUTODISCOVERY_FLAGS=5
09.04.2008 21:00:32 internet: INTERNET_PER_CONN_FLAGS=15
09.04.2008 21:00:32 internet: ERROR:HttpGetWininet, catch returned 0x00002F00
09.04.2008 21:00:32 general: InvalidateCurrent: invalidated server 'Download208 AVAST Server' from 'main'
09.04.2008 21:00:32 general: SelectCurrent: selected server 'Download507 AVAST Server' from 'main'
09.04.2008 21:00:32 package: GetPackages - set proxy for inet
09.04.2008 21:00:32 internet: SYNCER: Proxy enter01:8080
09.04.2008 21:00:32 internet: SYNCER: Type: standard HTTP proxy (rfc2616,2617)
09.04.2008 21:00:32 internet: SYNCER: Auth: no authentication
09.04.2008 21:00:32 internet: SYNCER: Proxy l/p: enterprocity\administrator/***
09.04.2008 21:00:32 internet: while trying to get file 'servers.def', error 0x20000004 has occured, try 10
09.04.2008 21:00:34 internet: tried 10 servers to get file 'servers.def', but failed (0x20000004)
09.04.2008 21:00:34 file: GetNewerStampedFile:GetFileWithRetry failed: C:\DOCUME~1\RCASSI~1.ENT\LOCALS~1\Temp\_av_proI.tm~a01604\onefile, servers.def, error: 0x20000004
09.04.2008 21:00:34 package: Tried to download servers.def but failed with error 0x20000004.
09.04.2008 21:00:34 general: Err:Cannot connect to download208.avast.com (75.126.203.66:80)