Stack corruption

[Jo=?ISO-8859-1?B?6w==?=l Guillod]

I experienced my first stack corruption yesterday... a bit disappointed
because I found RR very stable!

Is there a recoverable tool? Or should I read the file in a text editor and
try to rebuild manually?

How to avoid such corruption? I got it after importing about 200 files (4KB
per file) that I put into a field after creating a new card for each file.
There is also a save this stack instruction every 25 imports.

Joël G