Yes but then again there are physical limitations that are enforced by servers that are beyond our control.
If the forum is not on the same server as Photopost you can not use the integrated
vb header.
This would be the same internet limitation with cookies. Remember cookies can only be set for the domain that scripts are running on. Hense if you forum is on one domain and photopost another you can not have an integrated login.
There are certain things that can not be done.