Massive Error Logs/ .htaccess help

My site used to be http://forums.mydomain.com but I dropped the subdomain name and changed it directly to http://www.mydomain.com (over 2 years ago)
the forums Directory folder is still located in my files with an .htaccess file which contains the following:

RewriteEngine on

RewriteBase /

RewriteCond %{HTTP_HOST} ^forums\.mydomain\.com$ [OR]
RewriteCond %{HTTP_HOST} ^www\.forums\.mydomain\.com$
RewriteRule ^/?$ "http\:\/\/www\.mydomain\.com\/forum\.php" [R=301,L]

Which Does effectively change the urls from http://forums.mydomain.com/ to http://www.mydomain.com - preventing the pages from coming up broken. HOWEVER- in the error logs on my site,
every single redirect shows up- hundreds per hour:

Here's an example of the files:

2012-01-15 10:04:07.066 [INFO] [180.76.5.98:13687-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/404.shtml]
2012-01-15 10:04:07.066 [INFO] [180.76.5.98:13687-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/coupons-galore/54221-3-progresso-qs.html]
2012-01-15 10:00:34.418 [INFO] [46.165.197.142:46064-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/404.shtml]
2012-01-15 10:00:34.418 [INFO] [46.165.197.142:46064-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/freebies/6626-free-yummy-chummies-sample.html]
2012-01-15 10:00:32.901 [INFO] [46.165.197.142:45360-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/404.shtml]
2012-01-15 10:00:32.901 [INFO] [46.165.197.142:45360-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/freebies/6625-fitzmagic-free-magic-trick.html]
2012-01-15 10:00:31.277 [INFO] [46.165.197.142:44549-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/404.shtml]
2012-01-15 10:00:31.277 [INFO] [46.165.197.142:44549-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/freebies/66232-free-herbal-candle-beauty-herbal-spa.html]
2012-01-15 10:00:29.787 [INFO] [46.165.197.142:43849-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/404.shtml]
2012-01-15 10:00:29.787 [INFO] [46.165.197.142:43849-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/freebies/6623-free-veriunis-antioxidant-product-sample-bodymindit.html]
2012-01-15 10:00:28.171 [INFO] [46.165.197.142:43134-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/404.shtml]
2012-01-15 10:00:28.171 [INFO] [46.165.197.142:43134-0#APVH_forums.mydomain.com] File not found [/home/mydirectory/public_html/forums/freebies/6621-15-ae-money-card.html]


Things I've tried:

~deleting the /forums/ directory folder and removing the redirect htaccess note- this results in broken files/file not found which still creates an error and loses the visitor

~Removing the .htaccess redirection in the root folder htaccess- results in broken files/file not found

~

does anyone know of a fix/solution to this? My site error logs are massive each day from this

RewriteEngine On
RewriteRule (.*) http://www.example.com/$1 [R=301,L]


is all you need in the forums folder and will redirect everything to the correct place.