Those "infections" are a false positive, that only AVG seems to find.
The files in question are all in the Sun-Java cache directories.
You can delete them, but next time you use Java, they'll be back.
Just ignore the errors.
I once read somewhere that they aren't really false positives per se, but are only a threat to those running the old MSVM, which of course, nobody is anymore. I don't know how true that was.
