[Plugin: W3 Total Cache] W3TC and Rackspace and Subdomain Sites

So this should be sufficiently obscure to get no response … but I’ll try anyway.

I am running two WordPress sites on two separate installations.

http://www.mydomain.com
subdomain.mydomain.com

Both are hosted at Rackspace on their Cloud Sites.

W3TC was working just fine on http://www.mydomain.com before I added subdomain.mydomain.com to the picture.

Now, if I enable Page Caching, the .htaccess redirects in the Page Cache core section seem to confuse Rackspace. I keep getting one of their “system” error pages noting that the “site is temporarily unavailable”

My site root is set to http://www.mydomain.com. As such, W3TC has some rules such as “RewriteCond %{HTTP_HOST} =www.mydomain.com”

If I change this to “RewriteCond %{HTTP_HOST} =grc360.com” then all author pages work just fine. In other words, http://www.mydomain.com/author/myuserid works but http://www.mydomain.com redirects to mydomain.com and serves up that system error page still.

In addition, Pages vs Posts seem to work. If I go to http://www.mydomain.com/page everything is great. If I go to http://www.mydomain.com/hello-world, it redirects to mydomain.com/hello-world and serves up the system error page.

http://wordpress.org/extend/plugins/w3-total-cache/