If you are running vB3 now, you won't be able to run PhotoPost in vB2 mode.
There is a vb2 to vb3 upgrade guide in the FAQs section:
Converting from vB2 to vB3 FAQ
I don't think its a file permission problem; it sounds more like a configuration issue.
Might I suggest paying for the upgrade/installation service and having Chuck do it for you?