Issue with having a "." (dot) in the entity key

Question

I am trying to pass an ip address as a key to my service and realized that actually any key that has a "." dot in it, gives a 404.
I've tried escaping the "." with %2E, but no luck.

here is the fragment of the query string:
  myservice.svc/ipaddresses('10.10.10.10')
and that is returning me a 404.

However if I try
  myservice.svc/ipaddresses('10') , works fine

I can understand why the usual characters (i.e.: "/") need to be escaped but, what is the issue with "." ?

Answer 1

An MS guy pointed me to this KB article which fixed it: http://support.microsoft.com/default.aspx/kb/820129 (Appearantly, an IIS issue)
Needed to add the AllowRestrictedChars.