Your persistence is warranted. It may be one of two things I've thought of:
1) CMH may not currently support/recognize CMBS.
2) If it does, there is an extra step once you have Added a new game. It's tricky for me to explain without doing it, but even after you've entered the type of CM and the folder where the PBEM files will be found it will do a check and say it can't find the folder for CMBS. You have to Edit Game (right click on the game line in CMH and choose Edit Game), then go the bootom Application field, Browse and find the folder for the CMBS.exe.
Good luck.