[Elecraft] K2 drops receive level

[NZ8J]

I have a K2/100 that is exhibiting some strange behavior.  Sometimes it
has low sensitivity when I initially switch bands until I hit the "dit"
paddle and the sensitivity is then restored. For example if I use the
band + to switch to 20 meters and am on LSB/USB or Rtty, the sensitivity
is real low. As soon as I hit the dit paddle while in any of those modes
the sensitivity returns.  The strange part is I can cycle through the
modes and each time I change to either LSB, USB or RTTY the sensitivity
drops until I hit the dit paddle. When I cycle through the modes the
sensitivity is normal when I switch to CW. 

It doesn't happen all the time, but it seems to be doing it more often
lately. Also, sometimes while just listening to 75 meters ssb for
example the sensitivity will just drop off for no reason and when I hit
the dit paddle it returns.  I know I've probably not explained it well,
but you get the idea.  I thought it might be a bpf relay, but upon
checking further changing modes makes it happen also so I don't think it
would be that.  Anyhow I am going to look into it further this weekend,
but just thought I would toss it out there in the meantime to see if
anyone might have experienced this before..

Thanks 
Tim
NZ8J
K2/100 sn 5163
K2       sn 5295