Wireless with Roaming Profiles issues

I administer a Small Business Server 2003 Premium network which also has a
WAP connected for my wireless clients. I have six laptops on the network
that connect wireless - three use roaming profiles and three do not. Those
that use roaming profiles intermittently lose and find wireless network
connectivity, with some logons throwing the error:

Windows cannot locate the server copy of your roaming profile and is
attempting to log you on with your local profile. Changes to the profile
will not be copied to the server when you logoff.

Please help!

Mervin Williams