Reboots when trying to write to system!!!

[ironliver316]

I noticed a couple days ago that for some reason I wasn't able to write files to the system anymore. I tried using Root Explorer to copy some ringtones from the sdcard to the system, which I've done plenty of times, when I hit the mount r/w button, the phone reboots. So I figured I'd try to reflash (I needed to update anyways) So I backed everything up with Titanium Backup, reflashed, and nothing. Still rebooting in Root Explorer, but what's even worse now is Titanium Backup can't write to the system either. When I try to restore anything, it just reboots. I have s-off and typing "su" in Android Terminal changes $ to #. I hope someone can help, I really need my stuff restored.