WordPress and phpBB rewrite conflict

I’ve decided to use WordPress in the root directory of my site. In the /forums/ directory I have phpBB installed. I’m using modrewrite for friendly url’s for the forums, and when I set WordPress to use friendly url’s as well, it affects the forums they will not display properly when going into rewritten url’s (actually it shows a scrambled version of the wordpress blog). Also, the some of the categories in on the wordpress sidebar go missing… really weird.

What’s the best solution for this problem, I’m dead set on using friendly url’s for both directories.

Here is my htaccess for the forums:

Options +FollowSymlinks
RewriteEngine On
RewriteBase /

RewriteCond %{HTTP_HOST} !^www.example\.com [NC]
RewriteRule ^(.*) https://www.example.com/$1 [QSA,R=301,L]

RewriteRule ^forums/.+/([^/]+\.html)$ /forums/$1 [R=301,L]
RewriteRule [.]*-vf([0-9]*) /forums/viewforum.php?%{QUERY_STRING}&f=$1
RewriteRule [.]*-vp([0-9]*) /forums/viewtopic.php?%{QUERY_STRING}&p=$1
RewriteRule [.]*-vt([0-9]*) /forums/viewtopic.php?%{QUERY_STRING}&t=$1
RewriteRule [.]*-vc([0-9]*) /forums/index.php?%{QUERY_STRING}&c=$1
RewriteRule [.]*-ac([0-9]*) /forums/album_cat.php?%{QUERY_STRING}&cat_id=$1
RewriteRule [.]*-at([0-9]*) /forums/album_thumbnail.php?%{QUERY_STRING}&pic_id=$1
RewriteRule [.]*-apic([0-9]*) /forums/album_pic.php?%{QUERY_STRING}&pic_id=$1
RewriteRule [.]*-apm([0-9]*) /forums/album_picm.php?%{QUERY_STRING}&pic_id=$1
RewriteRule [.]*-full-asp([0-9]*) /forums/album_showpage.php?full=&pic_id=$1
RewriteRule [.]*-asp([0-9]*) /forums/album_showpage.php?%{QUERY_STRING}&pic_id=$1
RewriteRule [.]*-aper([0-9]*) /forums/album_personal.php?%{QUERY_STRING}&user_id=$1