You could try a Factory Reset as listed under "OTHER FUNCTIONS" in the
AVP-17 manual.
If you don't have the manual
LOOK HEREI have placed a lot of AVP-17s and haven't heard of this issue, but maybe tech support might know.
Also, the
AVP-18 "is" out and should be shipping soon
And while it may be quite obvious, check to make sure the
MUTE button on the remote hasn't been pushed.