Once you have put an exception for a file or folder...no scan will scan those folders.
be it Scheduled,Active/Quick or Auto-protect.
Main reason for scanning error is when the Decompresser engine cannot extract a file like CAB ,TAR...password protected files..
But once you put it under centalised exception it wont scan it...
Tamper Protection does not do the scan ( So no need to put these files or folders under Tamper Protection exceptions )