If you are getting rebootstraps I would go down this route;
When you next get an AP in this situation I would issue the following command from the controller CLI;
'show ap tech-support ap-name <name>"
I'd wait a minute and issue the command again.
The I would raise a ticket with TAC. (TAC will also want the output of 'tar logs tech-support')
With this output we can see the reboot reason, number of reboots, we can even see if the AP is transmittitng beacons i.e. operational.
included in 'show ap tech'
'show ap debug system-status'
This will show last rebootstrap reason and memory status etc
'show ap debug radio-stats radio 0/1'
This will show the RF enviroment, and number of packet transmitted received etc.
I don't think AMP version has anything to do with this issue.