Hi, I have the same problem, Ashserv blocks my computer using 100% of CPU, sometimes I can't move the mouse and winamp stop playing the music in background.
I'm using Avast Home 4.8.1195 on Windows XP Pro SP3, and I have only active the Standard Protection on Normal Mode, rest of modules are off. With prior versions of Avast didn't happens, i'm avast's user for several years.
The problem to be at large executable files, when i try to enter in a folder with this kind of files Avast blocks my computer while are scanning. For example, when i try to right-click or exploring folder with this files, avast uses 100% and blocks the PC:
308Mb -> WINDOWSXP-KB936929-SP3-X86-ESN.exe -> Windows XP Service Pack 3
431Mb -> VS80sp1-KB926609-X86-ESN.exe -> Visual Studio 8 Service Pack 1
493Mb -> hp_CLJCP1215_Full_Solution.exe -> Drivers Laser Printer HP CP1215
Once scanned can enter in this folder without problems for sometime, perhaps because they are in cache, but after a time, Avast returns to consume 100% CPU.
Greetings !!
PD: Sorry about my English, I'm a Spanish
EDIT: Mistake writing version of Avast installed, the correct one is v4.8.1195