Is there a way to use my CPG theme (I altered one of the standard themes to fit my website style) with phpbb? If not, is there a free BBS (that can also be bridged with CPG) that can use the same theme setup?
no, the coppermine themes can only be used with coppermine, no other app I know can use it, but you can modify most advanced BBS themes/templates/skins (matter of terminology) to match the look of your Coppermine theme. However, the theme engine coppermine uses is a spin-off from a very early stage of the phpbb theming engine (it never was compatible, but they used to be related closely). As both apps evolved, the theming has become more different, but if you're familiar with Coppermine's theming, you should be able to modify phpbb's theme as well.
Joachim
I've tried modifying the phpbb theme and I'm running into nothing but problems. Whenever I update the css, it leaves me with nothing but junk even when all I've changed is the hexadecimal values of the borders and/or backgrounds. I can't get it to recognize a background image and there's no recognizable template to allow me to change the layout. I'm looking for something easier to play with. I'm unfamiliar with php, so I'd prefer something that uses html templating.