hard to say what you did when you say updated here and there and this and that.
please do a syscheck.
How to post a syscheck: Instructions here
Also a brand switch can do wonders, get verbatim -R discs to burn your games.
memorex migth have changed discs quality, every stock differs and sometimes they even bring out like a discount sub-brand which is rubbish. (do not get the life series of the verbatim discs, good example).
do the syscheck and get proper media and we go from there.