Several users reported crashes when scrolling through a list of files with Atari800. I didn't have much luck in replicating this problem, and assumed that it was limited to custom firmware. I recently found out that this also affects version 1.50 units, and released an update that should fix the issue. I have posted more information at http://0xff.akop.org.
If you were experiencing crashes before, please give the latest version a try and let me know if the update works for you. Please post your experiences at the link above.