[Elecraft] P3 display "hanging"

[NZ8J]

I have a K3/P3(w/SVGA) connected to DXLabs Commander and the P3 display
"hangs" from time to time. By hang, I mean it just freezes for a second
or two periodically then starts working again by itself, I do not have
to do anything to restart it.
It seems to be connected to Commanders polling the K3 because if I turn
off continuous interrogation it doesn't hang up like it does with it on.
Of course that may be just masking another problem, I don't know.
I have used a K3/P3 (w/SVGA)combination previously with Commander and I
don't recall noticing this issue. I have the baud rates set correctly
and the latest firmware in both the K3 and P3. I have experimented with
the command polling interval but it doesn't seem to help much. 
I'm sure it's most likely some parameter I have not configured
correctly. If someone has come across this previously please email me
off list as this is most likely not a problem with DXlab or the K3/P3,
but it is something I don't have configured correctly either in DXlab or
the K3/P3 so I don't want to clutter up the group.
I've searched the archives and documentation but don't see anything
glaringly wrong with my setup.
Thanks 
Tim
NZ8J