OK so i have a 13" Macbook Pro fall 2011 model running osx 10.7.5 and I have been experiencing very peculiar bugs while using my computer. First and most frustrating is sometimes when I shut the lid it wont go into sleep mode. it will stay on until I open it and then sometimes the screen will come right back on and sometimes it goes to sleep. second, it won't shut down. When I try to shut it down in an attempt to reboot when acting funky, it will stay on the white screen with the little circular dashed loading sign on the screen for hours or until I force shut it down. third it won't update. when the software update window pops up I try to update the programs and it will freeze on the loading message moving items into place. this happens with all the updates (I have tried each one individually) fourth, time machine won't work or is incredibly slow and eventually freezes. Now these are still occurring after my attempts to fix it by resetting the SMC (which solved some of the issues like it would freeze 100% on startup and other debilitating things like that) ( the computer did also shut down once and has been better about going to sleep since resetting the SMC). all of the bugs happening now do not affect the performance as I can still use the computer fine. I have a virus protection program (eset) which I run on occasion but not all the time. I am a pretty savvy computer user and I don't have much data on the hard-disk, I don't crowd the desktop, I don't have a bunch of programs running in the background, etc. I am inclined to reset the PRAM but am not sure as I am somewhat new to mac OS and its processes. any help would be much appreciated. Thanks.