I am not sure what you are trying to report is your issue. We dont pull a members list from Invisionboard. The Integration module only authenticates the users login and can pull their stylesheet preference for the gallery to use thats it.
I would suggest since 99.9% of issues deal with misconfiguration that you make sure your invisionboard cookies are set like so
cookie path /
cookie domain .domain.com
You then install Photopost to integrate with Invisionboard and answer all the correct info. If you want us to look at what you got then send an email to email@example.com
with any sensitive information. I do not see anything here like site links etc that can help us help you. What errors do you get trying to login?