Far from always, not sure if saving new project, or 
modifying one. I am too new to WinHTTrack to avoid
simple-user errors :) Trash looks like instant shutting
WinHTTrack down without any msg.

Just now I made following experiment
1)created news project without category
2) set <http://www.atlas.cz/> 
3) set download pages, settings (AFAIK) default but deep=1
4) saved project - OK
5) done mirror with blinking protocol button
6) saved - caused crash ( seems reproducible by         
this way)
7) When loaded project again, none URL is displayed.