Fatal Crash Intercepted on Pinball FX 2

Hi all, I have a problem with my jtag I hope someone can help me with.

I have literally hundreds of hours of playtime on the xbla game Pinball FX 2 over about 5 years. It has always worked perfectly and I've added dlc and title updates as necessary without the slightest problem. Suddenly last week it crashed during gameplay (Fatal Crash Intercepted by F3 while navigating the main menu). Now every time I launch the game, it boots fine to the title screen, but when I press A to go to the main menu, I get the Fatal Crash Intercepted by F3 error and it boots me back to F3.

I'm no expert, but I'm not a noob either. I tried all the usual suspects:
- deleted all title updates and re-downloaded the latest through Freestyle
- Cleared cache through nxe
- Deleted all files in cache manually through ftp (There were 37 files in here, and clearing the cache through nxe had not removed any of them)
- Deleted the 58410A23 folder from my profile to remove any possibly corrupt saves
- Tried to run the game from nxe

When none of the above fixed the problem, I updated the kernel to the latest 17150 from the 16547 I had been using, then installed the avatars. Then I updated DashLaunch to the latest 3.14 - strangely, when I ran the dashlaunch installer, it didn't seem to install like it usually does, it just launched DashLaunch 3.14. At that point I didn't even know if it was booting up with 3.14 or the 3.08 I had been on previously. Freestyle was the latest version. Now, when none of this worked, I did the following:

- Uninstalled DashLaunch completely, along with Freestyle and all other homebrew I had installed except for xexmenu.
- Built a new nand with xebuild 2.095 and flashed it with Nand Flasher 360 as per InsaneNutter's guide. When I built the nand, I unchecked the two options "Include Dashlaunch" and "Include custom Dashlaunch settings."
- Removed all traces of Pinball FX 2 (as far as I know) - I deleted the 58410A23 folder from both the 00000000 folder and my profile folder, then double checked that the cache folder was empty.

Now, on this clean jtag with no DashLaunch, Freestyle or anything other than xexmenu on it I copied a brand new copy of Pinball FX 2, and it STILL crashes in the same place every time, only this time there is no DashLaunch or Freestyle to catch the exception so it just freezes.

It's important to note that I hadn't done anything to my xbox like updating the kernel or dashlaunch or even adding any new games, not even new dlc tables for Pinball FX for months. The ONLY thing I have done is add some mp3s to my external hdd and start listening to them instead of the in-game music.

All other games seem to work fine, X360, XBLA, XBLIG, even original xbox games.

I have spent hours reading this and other forums, but have not gotten any tips other than what I have already tried. Any help would be greatly appreciated.