Hmmm, I think you might be right. I'm sure it was created for some reason such as old phone browsers or easy printing. I think the issue is that google is indexing that version of the page instead of the normal one.
With a quick google search I found out that you can modify the robots.txt file to tell google not to index those kinds of pages, but I'm not sure if that has other consequences. I'm not sure if the mods should do it but it is something to think about
Disallow: /forum/index.php?*;wap
Disallow: /forum/index.php?*;wap2
Disallow: /forum/index.php?*;imode