Yeah i know.I was also saving the screenshots as jpg at 1024x768 and they were a lot smaller.
What i like is you can save a bunch of multishots at once and then choose which ones you like better.
Then just delete the rest.Open them in Gimp and save as PNG.Probably a lot smaller that way.
I always open them in RIOT myself.That program gets the file size down for you quickly with hardly any notice in quality.What i like about RIOT is you can input the size you want, and RIOT will try and get it there with the best quality.
A small hint about multishots - i used 4 for speed length, and 25 for shots and it still looks pretty good, as a GIF.