Instead of offering peace, try asking them to surrender. The AI's will do it if they're being beaten badly enough (and often less badly than you describe). That way, you get the war ended
and their worlds and ships besides.
EDIT - I see you tried surrender. In such a case, just ignore them and foucs on the greater task at hand. Some AI's are unfathomable (especially if the Anger settings are really messed up...). If you want to understand what's going on in the guts of your AI, go to
Fyron's Modding 101 page and the
Newbie FAQ.
EDIT - curses on all these quick-posters!
[ July 02, 2003, 22:46: Message edited by: General Woundwort ]