So you say that after a bouquet update via DBEDIT the box crashes, unless a Cross-EPG download hass taken place. Correct?

If so, the problem is in the reload of the settings on the box. That's one of the disadvantages of DBEDIT: it doesn't do this job properly.
Two solutions:
1- Stop E2 before the settings upload (init 4), and restart when done (init 3);
2- Use DramSet instead; that has the option to stop E2 --> upload settings --> restart E2
and DreamSet is a very good and userfriendly settingseditor.

Background:
E2 has (at least) the present bouquet list in memory, and a reload command doesn't always work (in fact that's a hack around this problem). If however E2 is dead on arrival of the settings, it does of course have no memory at all, so it will wake up with all fresh settings.