Lengthy post alert. I switched over from a PC to a MBP last fall because I was tired of the instability of PCs and Windows. Bought a 15 early 2011 MBP, 2GHz, 4GB RAM, 500GB HDD, Lion 10.7.2. Promptly upgraded the RAM to 8GB. Machine ran fine for a couple of months; very pleased. Here are the highlights of my troubles: A couple of weeks ago I started getting the occasional gray screen, need to restart kernel panics. They increased in frequency until a couple of days ago when I couldnt reboot. When into the recovery partition and found a keys out of order error rebuilding catalog B-tree, volume Mac HD cannot be repaired. Crap. Called Apple. Fortunately (or not well get to that part), I have kept Time Machine backups on an external HD. So at Apples suggestion I erased Mac HD and restored my system from Time Machine. I backed up a few weeks to exclude a few new programs that I was a little suspicious of. Anyway restore went fine, machine started booting again normally. Overnight, I attempted to create a brand new Time Machine backup on my external HD. I awoke to a kernel panic/gray restart screen. I restarted. I tried to verify discs my external TM disc gave an invalid node structure/cannot be repaired. My Mac HD gave an invalid key length. Was able to repair the Mac HD with disc utility back to volume appears ok status. At this point, I became concerned that my external hard drive Id been using for Time Machine was perhaps bad. So I bought another external HD. Formatted property and started creating yet another TM backup. Had two more kernel panics while trying to create the backup on the new external. Called Apple. Reset PRAM. Was told that might eliminate the panics. Continued trying to create a new backup image. Another panic. Called Apple. Suggestion was to reinstall Lion. Not ready to reinstall OS yet. This is why I bought an Apple in the first place stability. Crap. This whole time, I have also been suspicious of my Chrome browser not playing nicely, so I did kill Chrome and remove all of its pieces and parts from my system. After removing Chrome, I nuked my new (2nd) external HD and started again to make a new backup in Time Machine. Well, it worked. Created the whole backup with no kernel panics. System still up and running. However this morning, again on a whim, I ran a verify disc on the new TM backup, and guess what? Invalid node structure, needs to be repaired. And on my Mac HD invalid key length, needs to be repaired. Of course, now, I know what will happen when I try to repair it disc utility wont be able to fix it the external drive and it will become unusable again. And I will be able to repair Mac HD and it will be fine for an hour or two, but the next time I try to verify it, there will be another error. So basically, I have an unstable system which I cant seem to backup with Time Machine. Im currently copying over my actual data to yet another external disc just to save it. I suppose the next step is to reinstall Lion. But I wanted to get some opinion here first. I bought a Mac to get away from this sort of crap, and Ive now wasted the better part of 3 days on a very PC-like experience of instability.