Pavilion dm4 w/Windows 7 - 64: image goes jagged and system freezes, alternately sometimes reboots?

[_ML_]

Pavilion dm4 w/ Windows 7 - 64 bit Laptop: All HP updates are current, windows updates current, and I recently re-installed HP Support Assistant because I was getting a message that "CASLExec" was crashing and had stopping unexpectedly.

My system is pretty new but I have been having two problems with increased regularity:

1) The screen image goes jagged (brighter and more concentrated on the top-half of the screen) and I am unable to tell if it has frozen or is strictly a screen image problem.

2) Alternately, sometimes the system suddenly reboots without any shutdown. This has happened both during use as well as when not doing anything at the time of a reboot.

I do not know if I should hope that the two problems are related or not, but  it would be nice if a single fix corrected both problems because they were caused by the same root-problem.

Q: There may be a connection between these issues and the system asking about switching it's graphics acceleration from graphics board to system resources when the laptop is not plugged into a wall outlet?

Q: Has anyone any idea of how to go about troubleshooting this or fixing this?

Q: If it is a graphics hardware driver issue, is there an updated driver by the component manufacturer that maybe HP just hasn't included in a support assistant update?

Thank you in advance for any help or advice!