I have been recovering from the loss of 700GB of data and a logic board. Since Apple, in it’s wisdom, decided to wipe my internal drive when fixing the graphics card, I had to restore my data (as much as I could) from my Time Machine backup.
After that, I set up my new external drive, a Seagate 500GB Free Agent drive with a case, as the new Time machine back up drive. And i left it to back up over night.
The next morning I had lost the ability to drag-and-drop. I could select any file, even open applications, but I could not drag them anywhere. Couple of quick searches on the net turned up some cryptic mentions of permissions. I tried to repair them, twice. but nothing helped. I finally resorted to booting from the Mac OS X disc and doing a re-install of the system software (the one that keeps the settings and content, not the one that wipes the drive). That fixed the issue quite nicely.
I still don’t know what happened. I have no idea why it would be working before bed, but then not the next morning. Since then the computer has been wonderful. It’s great to have the storage, and with a recent battery purchase, it’s almost like having a new laptop.