Just want to report that I recently came back to CoH and have been having this issue too the whole time I've been back. I have the game running on a brand new Win7 install on a brand new SSD. This is a dual-boot system, so I only use this Win7 install for playing CoH; no other application software is installed, the latest production Nvidia drivers are installed and no anti-virus software installed yet. My video card is an EVGA 460GTX with 1GB of memory. The system has only 2GB of DDR2 memory, so at first I was thinking that maybe I was running out, but that doesn't seem to be the case.
Symptoms are similar to what other people are reporting: exit mission, and every few times the game slows to a crawl for a few seconds, and then it halts. I ALT-TAB and sometimes there is a system message about some incompatibility with the current Aero interface which is the default Win7 setup. I clear any error messages, if necessary, force CoH to close, and then restart the game and get back on my team.