g1smd - 9:35 pm on Aug 18, 2010 (gmt 0)
Your line of code:
Redirect 301 /subdomain/ http://subdomain.example.com/
will be problematical.
As it says above, do not mix Redirect and RewriteRule directives in the same site. Use RewriteRule for all of the directives and mind the order of them all.