Desktop settings for explicit policy messes up modem type

Ok here is my problem:

When I change explicit policy’s desktop settings and changes take effect on users,

then their modem type is changed to “.autoconfigured”.

So that they can’t get dail-up connection to server anymore.

Quite annoying to manually set it right or by phone explain to users,

how to set their modem type back to the right one.

Have anybody solved this little “feature” or have remedy for it?

Thanks in advance