Adjusting htaccess in order to remove double / bug

Question

After creating a toplevel catagory with sub-categories, I noticed double slashes in the recent activity list when clicking a category (not necessarily a top level » sub)

I get URLs like:

www.domain.com//politics

But, this only happens on the frontpage (recent activity page).

So I thought I fix this by putting some code in htaccess... but this does not work either!

DirectoryIndex index.php
<IfModule mod_rewrite.c>
RewriteEngine On

# q2a permalink structure
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^.*$ index.php?qa-rewrite=$0&%{QUERY_STRING} [L]

# remove double slash
RewriteCond %{REQUEST_URI} ^(.*)//(.*)$
RewriteRule . %1/%2 [R=301,L]

</IfModule>

Does someone know why this not works?

Comments

My Q2A site shows "//" in homepage only and in firefox, but chrome shows no double slashes.