[Elecraft] PSK31 using data mode

[Elmore's]

I have encountered a problem using PSK31 in data mode with my K2. I have 
been successfully using PSK31 with a homebrew interface for several months 
with the K2 in USB mode. I recently decided to use PSK31 in the data mode to 
take advantage of its automatic selection of no compression and its DSP 
selection of no noise reduction and no auto-notch while allowing me to have 
my own bandwidth selections just for PSK31. My software is Digipan.

The problem that I noticed is that the receiving frequency of a station I am 
watching on the waterfall is actually approximately 1 KHz higher than its 
actual frequency. For example, a station could be transmitting on 7070.5 and 
I will see its signal on 7071.5 and nowhere else (i.e. "ghosting" is not 
occurring). I determined this by conducting a test with a nearby ham. I 
assume that I am also transmitting on that same frequency (7071.5) although 
we were unable to verify that. I am certainly not transmitting on the 
correct frequency since I was never able to make contact with anyone over a 
number of attempts. I have generally had no problems conducting QSOs with 
anyone.

Has anyone else seen this problem or have a possible solution?

TNX & 73, Jim  WA4YWM