Winrar Issues CRC Errors

This is a very weird problem. Anytime i download .rar files from the internet, it doesn't seem to matter if its a set of 50, 200mb files. or single files that ar anywhere from 40-100mbs i get completely random CRC errors in those files.

Example 1: I downloaded a set of 57 200mb files, and files 08,10,11,12,24, and 36 are corrupted. However if i re-download those files i will have a different set of corrupted files.

Example 2: I download a set of random sized files anywhere from 40-100mbs each all single files not .001 style setup of rar files. perhaps 2 or 3 of those files will have files inside that are corrupted. However if i wait a short while, and retry rarely but sometimes, they actually work, and do not seem to be corrupted. Sometimes after 3 or 4 tries they are still corrupted.

Example 3: I had a set of files totaling around 8gigs and i decided to pack them up. So i compressed them in rar format. to double check my work, i uncompressed them immediately and used them. they worked fine. around a month later i needed those files again and i uncompressed them again. around 4 of the files were corrupted. Every time i unrar them its the same files that are corrupted.

Many files have been downloaded off of rapidshare but not all.

I have already updated all my drivers to the latest including BIOS drivers
I have tried this problem on Winrar and 7zip same problem on both.
I have been advised my problem could be having a messy registry so i have used registry cleaners to no luck.

My current system setup is:

Asus Striker II NSE
2GB of OCZ DDR3 PC3-10666 Fatal1ty Edition Ram x2
Nvidia 9800 519mb x2 SLI
WD Raptor 150gb x2 Raid 0
Windows7 Professional x64bit
(also had this same problem on Windows7 Ultimate x64bit)