We added a Uniden Dect 6.0 system (the DECT1580

We added a Uniden Dect 6.0 system (the DECT1580 Series with three handsets) to our home. We already have two wired phones connected to the same line.

When we receive an incoming LONG DISTANCE call and answer with handset No. 2 (not the one on the base), the handset dosn't answer the call (callers tell us that the phone rings without end) and we hear the line tone in the handset...

When the incoming call is a LOCAL call, handset No. 2 answers the call OK.

Also, handset No. 1, the one on the base, answers LONG DISTANCE calls OK...

Finally: if we're already on a call using handset No. 2 and a LONG DISTANCE call comes in (we have the "call-waiting" service), then handset No. 2 is able to take the long distance call normally...

Any clue? Thanks!