why doesn't this regular expression get recognized by codeigniter's router

[eluser]codeigniterzzz[/eluser]
I have this route:

Code:

$route["((parameter|type|something)-([0-9]+)\/)+"] = 'somecontroller';
so when i test the url with this:

www.somewebsite.com/parameter-1/

codeigniter returns with a page not found error. But I tested the regular expression here:

http://rubular.com/

and it seems to work perfectly fine.

I have also tried putting the leading/trailing /'s:

Code:

$route["/((parameter|type|something)-([0-9]+)\/)+/"] = 'somecontroller';