[Asterisk-Users] Question on SPA-2002

[Matt]

Hi,
I have about 53 SPA-2002 units out in the field.   I've seen two or
three of them, now, exhibit an odd happening.

Users plug their phones into LINE1 (unless they have two lines).   The
two users I've had issues with are both employees here who are fairly
knowledgeable in computers.  They both were using portable phones and
that was the only phone they used (so no trying to back feed the house
or anything).

Both of them started using the service with the device around October
of this past year (2005).

Just recently both of them have come to me and said they could place
outbound calls just fine, however inbound calls go to voicemail.  I
did some looking and the ATA is sending a "Busy" message back to
asterisk. (Even when the phone is on hook).. (Even when the phone is
unplugged!!).

I moved the config and the phone to LINE_2 and all is well.   Any
thoughts on this?