Cindy...
If you have tried all the spyware scanners... with nothing coming up-- I would look to software conflicts.
I notice from your
HJT log that you have:
Norton Go Back/Ghost
BigFix clients both running at the same time.
I personally just uninstalled Bigfix's client --as it kept hanging at bootup. Whether this problem is related to your issues -- i don't know... but it's worth a shot. I've used BigFix for years-- and I do intend to reinstall it-- I believe that perhaps it got corrupted, or a new Windows Update 'broke' it.
I would run msconfig... and uncheck anything related to these 2 progarms-- and everything else not absolutely critical. Then Reboot.
If you are unsure of a process's origins --then google the exact file name... you should be able to figure out what it is/does.
Then you can slowly, one at a time... re-enable your programs and see if the symptoms return. You could just have too many things-- especially somewhat similar apps --all running at boot.