excuse me, i posted my local htaccess, not the one on the server...
Options -Indexes +FollowSymlinks
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([^:]*):(.*)$ /index.php?a=$1&p=$2 [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([^:]*)$ /index.php?a=$1 [L]
The 2nd rule was for single variable commands, for some reason I couldn't get a single hyrbid rule to work.
I don't know why I didn't try testing direct file access before... but I did and it double posted again. I also tried test.php, which is just a blank file i uploaded, and it did a single post to the database...
That would seem to imply it's my rewrite rule that is off then, though I'm not sure what.