御迷惑をお掛けして申し訳ございません。

Excite翻訳: I am sorry for multiplying the trouble.
@nifty翻訳: I am sorry to have made trouble.
Babel Fish: We applying annoyance, there is no excuse.
Google翻訳: We apologize for the inconvenience that you're sorry.
Yahoo!翻訳: I am sorry to do credit of a nuisance.
OCN翻訳: I'm sorry to cause you trouble.
Windows Live Translator: the trouble to, sorry.

Summary:
@nifty and OCN give expressions you may hear in a real situation.
However, @nifty's result may be too casual;
OCN's can be used before an incident, e.g. when asking for help.