MacBook sleeps right after resuming from disc

Hi All,

My MacBook Pro (late 2012 MBP 13" i7) has been acting up since I got it but it's finally annoyed me enough to post a question to the forum. The problem is as follows:

1. Mac goes into safe sleep mode
2. Battery runs out of power
3. I connect the external power supply and leave it a minute or two
4. When the Mac resumes it has to load the hibernation file from disc
5. There is a long pause after the loading bar fills
6. The Mac then goes straight into sleep mode

Once the hard disc has spun down I can press any key to restart the computer. Although the memory is still powered, and so can resume immediately, the Mac still takes one to two minutes to become responsive enough to let me type in my password to get back to the desktop.

Why I got my MacBook Pro I migrated all my data, programs and settings from my old MacBook. I had a suspicion that I may have brought across an incompatible OS extension or something but I've not been able to find any likely suspects.

Any help/advice/pointers would be greatly appreciated!

Dave