Your first RewriteRule will be the one always invoked (i.e., it matches anything and everything), and send your visitor off to
www.gamebits.net. Is that what's happening to you? Is
gamebits.net an add-on domain? Depending on how your server is configured by LP, that add-on may show up in
.htaccess as either
gamebits.gagne-enterprises.com or
gagne-enterprises.com/gamebits/. You may or may not be catching
gamebits.net in the RewriteCond.
May I assume that
public_html/gamebits/dc/seaman/ contains an index file? The default setup is to look for index.html, then index.htm, and finally index.php. This can be changed with a
DirectoryIndex command.
Your RE pattern of (.*)\.shtml is not going to trigger because .* will grab everything up to and including .shtml. Try changing (.*) to ([^.]+) and see if it stops grabbing (into $1) at .shtml.
You can combine the two RewriteCond lines:
RewriteCond %{HTTP_HOST} ^(www\.)?gamebits\.gagne-enterprises\.com$