Joining the club (avatar/sig related)...

For the web, I think Square Pixels Ratio 1:1 is what you need. Then change the document size width/height instead. Under File > Export there's Adobe Media Encoder which has alot of options but I don't know if it does Animated GIF. You can also try reducing the fps and quality % settings.
To be honest though, i'm forever having headaches over exporting video... :x
(Ruri_Ayanami from the old Tex Murphy ezboard).
"I don't believe in intuition, don't know why... just a feeling." - Tex Murphy