Are these safe? - trojan hunter report

Hi, I have been experiencing some weirdness on my pc lately, and whenever I scan with DrWeb cureit, it finds Trojan.StartPage.1505 throughout system restore, and also Spybot backup. It is always a .reg file.
Sometimes the computer has been close to crashing, and I'm occasionally getting error must close messages from DrWtsn32 which is running two instances and seems to have frozen.
I have scanned with trojan hunter, a2, ewido etc and none report any trojans, but I have just cleaned any drweb found (6) yesterday.
But they keep coming back!
After scanning with trojan hunter it found these;

Warning: Unable to unpack UPX-packed file C:\Program Files\a-squared Free\a2free.exe (Add to ignore list)
Warning: Unable to unpack UPX-packed file C:\Program Files\Common Files\Autodesk Shared\adresc16.dll (Add to ignore list)
Warning: Unable to unpack UPX-packed file C:\Program Files\Rockstar Games\GTAIII\gta3.exe (Add to ignore list)
Warning: Executable file with double extensions found: C:\WINDOWS\assembly\GAC\Microsoft.VisualBasic.Vsa\7.0.5000.0__b03f5f7f11d50a3a\Microsoft.VisualBasic.Vsa.dll
Warning: Executable file with double extensions found: C:\WINDOWS\assembly\GAC\Microsoft.Vsa\7.0.5000.0__b03f5f7f11d50a3a\Microsoft.Vsa.dll
Warning: Executable file with double extensions found: C:\WINDOWS\assembly\GAC\System.Web\1.0.5000.0__b03f5f7f11d50a3a\System.Web.dll
Warning: Executable file with double extensions found: C:\WINDOWS\assembly\GAC\System.Xml\1.0.5000.0__b77a5c561934e089\System.XML.dll
Warning: Executable file with double extensions found: C:\WINDOWS\assembly\NativeImages1_v1.1.4322\System.Xml\1.0.5000.0__b77a5c561934e089_66c56f6f\System.Xml.dll
Warning: Executable file with double extensions found: C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\Microsoft.VisualBasic.Vsa.dll
Warning: Executable file with double extensions found: C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\Microsoft.Vsa.dll
Warning: Executable file with double extensions found: C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\System.Web.dll
Warning: Executable file with double extensions found: C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\System.XML.dll
No trojan files found

I am assuming that the unpackable files are ok, but what about those with double extensions?
Thanks, argus