Are you being sent to "m.yahoo.com" or "m.
www.yahoo.com"? If the latter, then this is by design -- the folks at Yahoo have a redirect enabled.
If you had redirects disabled, then you would see this message:
The document has moved <A HREF="
http://m.www.yahoo.com/">here</A
>.<P>
However, most browsers will immediately redirect you. This is normal, and may be done for performance or load balancing reasons.