[Elecraft] "K3 VFO A Not Responding" message

[RLVZ at aol.com]

Hi Guys,
 
Hoping someone can help me fix the following problem which is driving  me 
crazy:
 
For the past couple of years, on the top of the N1MM Logger screen, I often 
 get the message "K3 VFO A not responding.  When I get this message  my 
computer is locked up and I'm unable to log or transmit.  A very  bad problem 
to have when running stations during a contest.  The  problem seems to occur 
aprx. every 15 minutes when operating RTTY and aprx.  every 30 minutes on CW.
 
People have told me "you have RF getting into your system.  So for the  
past 2 years I've been putting double chokes on every cable connected to the K3 
 and logging computer.  And I endlessly keep working on grounding all of my 
 equipment better.  When the problem didn't get fixed, I  replaced all of 
the cables but that didn't help either.
 
I've tried 4 different Windows XP computers, and 2 different Windows 7  
computers.  All computers have given me about the same number of "K3  VFO A Not 
Responding" error messages, except for my Office computer which  runs 
Windows 7 and has a Quad Core processor, this computer will often  operate a 
couple hours before giving me the dreaded ""K3 VFO A Not Responding"  message.  
(so that's much better than the other computers)
 
A few other thoughts:
 
-I've received these error messages whether running 100 watts or 1,500  
watts so I'm not sure high power is the problem.
 
-I've had the dreaded "K3 VFO A Not Responding" message occur while  
receiving, though it usually occurs while I'm transmitting.  So I'm not  sure 
transmitting causes the problem.
 
So I'm wondering if the problem could be with the K3?  Perhaps I  should 
try a different brand radio to see if the problem goes away.
 
Has anyone else frequently had this terrible "K3 VFO A Not Responding"  
message occur to you?
 
Thank You in advance for your recommendations. 
 
73,
Dick- K9OM