Well according to the errors you have given and the CBS log you have system files that are getting corrupted.
It could be possible you have a rootkit that is hiding what is damaging your files.
To check for rootkits scan your system with TDSS killer by kaspersky which can be found here - [size=78%]http://support.kaspersky.com/faq/?qid=208283363
I know you have said you reinstalled,but rootkits can burrow down deep into your system. It can even go so far as to going into the BIOS.
Also do you have an install disc? If so have you tried running a repair install? A repair install simply re-installs all system files.
Do you remember when this problem started happening?