I was playing Hexen a bit, and then decided to try saving my progress in a savegame.
After that, I quit and restarted Dingux again. At some point, I noticed the message 'Deleting fat entry beyond eof', after which 'Mounting in read-only mode' was applied to the SD Card. This usually hints at a filesystem corruption and Linux' attempt to limit damages.
Next thing, I got the Segmentation fault while trying to start Rise of the Triad. So I would say your 'Segmentation Error' could have to do with a corrupt filesystem on your SD card.