VS Addin : connecting to several TC instances with different versions

Hello,

I am currently working for several clients that use TeamCity. One of them uses teamcity 6 and the other uses teamcity 5. I have upgraded my addin to v6, and I cannot connect to the TC5 instance without downgrading. Is there a magic switch somewhere I can use to use the TC 6 addin to connect to TC5?

Do I need to create separate vs.net hives?

Cheers,
Florian