Compression/archiving programs (such as Winzip, Winrar) give you the option of encrypting your archives with a password. You must have your antivirus set to try to scan inside compressed archives, but you have a couple of password-protected ones on your hard disk.
This isn't necessarily a problem - they could be used by an application and are passworded to stop people prying. (where I work we have applications that do this, so it's not unusual)
You'll find your scans take less time if you turn the 'scan inside compressed archives' option off, but that's up to you of course... Personally I wouldn't bother scanning inside them.
Back to your original problem, I suppose it <i>could</i> be a weird BIOS bug or something, but it's not one I've heard of before. You could try flashing the BIOS to the latest on the off-chance (but that can be potentially risky, although it's generally 99%+ safe if instructions are followed carefully), or maybe send an e-mail to the board manufacturer maybe.
Not sure what else to suggest, really.
---
<font color=red>"Life is <i>not</i> like a box of chocolates. It's more like a jar of jalapeńos - what you do today might burn your a<b></b>ss tommorrow."