According to the Dosbox homepage, No Regret is 100% supported in DOSBox 0.61 and No Remorse 90%. But there is no description what to do to prevent errors. - Only info is, that others get crashes / errors as well.
Oh well, I guess the guy who fixed it never posted how to fix it :S
So best might be to also check the dosbox forum's for help...
EDIT: Xerxes is noit the only one with such low fps. I've just checked the dosbox forum. Hmm, you might want to try out a newer cvs, though. Maybe it's faster with that game. Here is a link to gulikoza's side with a compiled version: http://home.amis.net/lkslavi
the main page? that is http://dosbox.sf.net
or did you mean gulikoza's dosbox section? that one is linked on the left at the side I linked in my previous post.