Yes, each save contains the complete data for that point in the game, so something corrupting the last 5 saves of a particular character is unlikely. One person had a crash a few minutes after exiting DD. After rebooting, Windows (or something else) had deleted the inv.b2 file from all of their saves; fortunately it is a zero byte file, so was trivial to replace.
It is possible something in the game was corrupted for that particular character (assuming you have two different character types on the go). Try starting a new game with the same class and gender as the character that crashes, and see if you can save and reload it.
If the new game crashes as well, you could try a clean reinstall of the game, as described in the
Troubleshooting Tips topic (or try the file verification procedure, since the install program has problems on your system for some reason).