General Support: modifing the installation process

im working on making an installer to create a plogger community and ive run into a problem that i cant seem to figure out how to resolve. i want to install all the community ploggers into a single database, so each plogger install will need a diffrent table prefix. ive added a form to the installer that ask for a table prefix, and then when it installs it installs with the table prefix and everything goes fine. thats when we run into a problem. when you load index.php, the gallery.php script looks for things that are hard coded with the old "plogger_" database prefix. i tried to replace this with the var created from the input form, but it doesnt work, i still get errors. if anybody understands what im talking about, can you help me? thanks!