Problem with SEO urls and the Find_By_ID() not working

I have a problem where the app I am developing uses SEO friendly urls
using the to_params method.

When using the the finder method find_by_id(‘13-Some-other-text’) it
is not finding the record.
The record is there.
If I put a to_i() on the value it works fine.

I thought ActiveRecord did this automatically

Steve