Hi Nathan,
The whole DTA folder could be corrupt.
I would say try upgrading the firmware of the SVMI-20, from memory the latest is 5.4.1.1?
If i remeber correctly you will also loose the programming but by the sounds of it this isnt a bad thing if the VM is corrupt.
I would say to backup your DTA, MSG, MBX and PMT folder just to be sure but dont re-upload the DTA folder as this will downgrade the SVMI-20 to the old level again. (hence why you need to prgram from scratch).
I hope this helps.
Phil