Hi:
I have a 650, but this was fairly common when using Documents To Go to view Word or Excel files. If that is what you are using, take a look at this Palm article:
http://support.dataviz.com/support.srch?docid=13568
I can tell you that after installing the DataViz Tech Tool I have not had a reset opening documents since. I got the impression their Tool also applies to the 700p.
Let us know if this helps or if not, perhaps you have one file with corruption. Does that file open on your desktop system?
SteveTaz