htaccess : redirect an iphone user unless

I've been reading up on the syntax for constructing htaccess rules but no matter what I try, I can't get to do what I want to do.

I am aiming to redirect all iphone visitors to a subfolder on my domain, easy enough:

RewriteCond %{HTTP_USER_AGENT} iPhone
RewriteCond %{REQUEST_URI} !^/iphone
RewriteRule .* http://domain.com/iphone/ [R]

This successfully redirects iphone users who aren't already trying to go to http://domain.com/iphone. However, I don't want to redirect users who are trying to go to domain.com/app (this url has its own redirect to an apple app store page, so i want iphone users to be redirected there as well, rather than the ip开发者_开发百科hone version of my site). I tried this:

RewriteCond %{HTTP_USER_AGENT} iPhone
RewriteCond %{REQUEST_URI} !^/app
RewriteCond %{REQUEST_URI} !^/iphone
RewriteRule .* http://domain.com/iphone/ [R]

I thought that the /app condition should work in parallel with the /iphone condition, but it seems iphone visitors to domain.com/app are still being redirected to munch5aday.com/iphone/.

Very grateful for any suggestions!

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Add the line RewriteEngine off to the directory's .htaccess file.

Adding answer now to avoid this question being listed as unanswered. Answer is based on questioner's comment in December 2010.