Dang how do u clear a cache on a ps3?
I am not sure if there is a settings in the options for the PS3 or not. Try googling "clear cache on the PS3" and see what they say there.
If you can, try saving your games first, and then, maybe you will be able to copy them back in again. I know you can't do this for the 360, or I haven't figured out how on the 360, so not sure if it's possible on the PS3.
Also rememeber once you re install it again, will the PS3 not just install the latest patch again? So you might have the same problems again. Just save your games first, if possible, then try it out.
Good Luck.