I just upgraded my gallery to 5.3 as part of a complete site reorganisation. The only problem I ran into was with the change to my forum database table naming. Originally I did not have a prefix for my VB forum tables and as such did not have any prefix in the admin settings. But this time around, I changed my table to have a prefix which could not be changed anywhere outside of PP and as a result, my gallery wouldn't work. I had to go into the database itself and update the settings table.
May I suggest that you put a variable into either config-int or config-inc to enable people to define their forum table prefix outside of the PP admin area.