Appache mod_rewrite and CI routing

I have this line in my .htaccess file:

Code:

RewriteRule  "^rpc/(.+)"  "/rpc"  [PT]

It redirects all `/rpc/something` requests to `/rpc`
And it really does, but when CI Router processes the request it still uses the full original URL `/rpc/something`

Code:

message: "Can't find a route for 'post: rpc/something'."

This is some $_SERVER vars:

Code:

["REDIRECT_URL"]=>string(4) "/rpc"
["REQUEST_URI"]=>string(12) "/rpc/something"
["PATH_INFO"]=>string(4) "/rpc"
["PATH_TRANSLATED"]=>string(23) "redirect:\index.php\rpc"
["PHP_SELF"]=>string(14) "/index.php/rpc"

May be CI should use REDIRECT_URL instead of REQUEST_URI?