Raise your hand if you saw the topic title and immediately screamed Noooooo!
This is what I have in .htaccess file
Where? Under the new domain or the old one? Or are they parallel domains in a shared userspace?
<IfModule mod_rewrite.c> RewriteEngine On <snip> RewriteRule ^/?$ "http\:\/\/\newdomain\.com" [R=301,L]
... Now wait a minute. I swear I saw this IDENTICAL rule configuration-- IfModule, RewriteEngine On, RewriteRule with conditions, close IfModule, and finally a domain redirect with superfluous escaping-- in another thread no more than two or three days ago. So you can simply dig it up and swipe their answer :)
it's almost incredible to see the same set of unusual errors on two consecutive days.
regarding your current .htaccess file: - before you fix anything you should reconsider your decision to redirect all urls on olddomain.com to the home page of newdomain.com - it's not a good experience for the visitor and google will at best treat this like a soft 404 and at worst penalize you for manipulation of pagerank. - if you are redirecting all requested urls to another domain you shouldn't have any requirements for an internal rewrite.