I am currently implementing the Maxcoin algorithm on cgminer 3.7 codebase, this should solve the crashes issue. The background here is that I have initially forked and fixed the version Maxcoin project has put on their github, but that one was 3.6-based, and 3.6 is prone to crashes and does not perform as well.

Regarding your CPU mining issues, would you plese PM me the address you mine with so I could do a little investigation?