Not sure if you're still working on this, but here's some more notes:
I've been trying to play AYBABTU several times over the last week or so with expanded AI enemies and a few more systems for a greater challenge, and the level crashes Eufloria every single time after about five to ten minutes of play
Not sure exactly what the error is, later tonight I will copy the application error message from Windows 7.
Another bug I have noticed is that forces traveling to another system will on rare occasion turn to a negative number. This happens sometimes after your force encounters and wipes out an enemy force coming towards you along that same string, but I haven't observed it closely enough to reproduce it predictably. The continuing negative force then will add to your enemy upon arrival, or you have to send additional forces along the string to turn the number positive. Clearly some kind of arithmetic error going on
One other suggestion: it would be very helpful to have a way to cancel an autosend route after you have established it.