[Elecraft] K3 HRD/DM780 PSK31 problem

[Twan at pa0kv.nl]

Hi!
I'm having troubles with transmitting PSK31.
Normal setup which worked perfectly for several years.
Setup: K3/100, HRD/DM780, separate sound card line-in/line-out to K3 
line-out/line-in.
PTT control by HRD, K3 VOX ON and K3 MIC SELECT on LINE-IN.

For several day I can't make a QSO.  I receive perfectly but when I 
call, no answer.
Also calling CQ on 15m with the band wide open, no answer.
The K3 is putting out about 30 watts, antenna (yagi) and SWR are 
perfect. I also hear the normal sound of transmitting from K3's monitor.
It look like I'm receiving and transmitting on different frequencies. In 
HRD the offset is zero (0).
Using USB or DATA A makes no difference.

Another thing I noticed; when HRD is finishing a CQ macro, K3's 
transmitting output drops to zero but PTT stays active.
Pressing the XMIT button twice will release PTT and K3 go on receive 
again.  K3 VOX DELAY is zero.

Are there any config settings I might messed up? Or hardware issues?
I reinstalled HRD/DM780. No effect.

CQ CQ CQ....

73s, Twan - PAØKV

K3 - 1770