I'm intergrated by following this instructions: http://community.mybb.com/thread-87200.html
You did not do Step 3. Template Edits for Coppermine 1.5.x (In template.html, remove all the content between <DOCTYPE> and {CUSTOM_HEADER} and all the content below {CUSTOM_FOOTER}) and Step 6. Wrapper for MyBB 1.4.x/1.6.x (Remember the template.html <head> items you saved when modifying that file? Now is the time to add those into the $headerinclude variable at the bottom of the wrapper. Otherwise you will loose the features of the CPG theme you are trying to implement. Do NOT overwrite the $headerinclude, but append to it.)
Those steps are mandatory for things to go right.
At step 7 Templates for MyBB 1.4.x or 1.6.x he includes forum title in the code:
<title>{$mybb->settings['bbname']}</title>
That's not a mistake, but makes coppermine use the forum title not the coppermine title (up in the browser will show RCLanka Forums, not Home - RCLanka Gallery.
Here
http://www.communityplugins.com/forum/mydownloads.php?action=browse_cat&cid=10 you can find cpg mybb wrapper Version 1.4.0. It works just like ver 1.1 (the one you have). It also contains a mybb wrapper plugin for MyBB to add in forum_folder/inc/plugins but is not compatible with MyBB 1.8. I do not know what mybb wrapper plugin for MyBB can do in plus.
LET ME KNOW if the solution works for you.Install instruction can be found here:
http://community.mybb.com/thread-87200.html but they are very short. For begginers can be hard to understant so I posted a step by step tutorial since this plugin is a coppemine plugin.
CPG MyBB Wrapper plugin for MyBB and coppermine bridge - install instructios
http://forum.coppermine-gallery.net/index.php/topic,78228.0.html