Hi - when Notes 8 was released, we ran c.Support v2007 through versions of mixed server and client, from versions 6.5 to 8 and did not run into any issues.
Based on what you reported, I have additional questions that may lead to why you are seeing this behavior. Would it be possible to contact our support center and have them gather information and help with troubleshooting? They will need things like your c.Support version and code date, Domino server & client version, and also if any critical fix's have been applied to Domino.
Thats going to be the best way to track this down, and hopefully its a minor thing.
Lisa Kienle
GWI Software