If you got black market games then uninstall it. Try to do hard reset and see if the reboot stop. Are you still on stock rom or custom rom already?
What games is it? Some games are badly written and can freeze your phone. Or are you playing games while charging your phone?
Try to clear your cache first. Go to setting > applications > manage applications > all > market > clear cache
If still cannot then do a hard reset.
If still cannot, uninstall market and then install it back.

Using Market Enabler still can't get it. Maybe not yet roll out? Wait til later evening then try lo

I have a question. I read that you guys download Ps1 games into the phone etc. Where do you actually get them from? 

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Added on August 11, 2011, 8:25 am

Try recall which app you recently download and try one by one (uninstall) and see which is culprit. Worst case, hard reset, full wipe, wipe cache and dalvik. After that, install back some of the apps and try one by one.

which one are you choosing? saw this from other forum, 2000mAh battery pack from samsung, with special design case...a lile bit bigger.