[1000mp] Sub RX sounds like shift is not in the middle position (ft - 1000mkv)

[DL3HBY]

Hello all-

first noticed that my monitored signal sounds too high or too low in 
frequency (usb or lsb)
After looking twice - it`s the sub rx . In the first 30 Minutes after 
switching the rig on, the rx signal sounds like
it is not in the middle of the rx filter.
After worming up , the monitored and rx signal on the 2nd rx is ok.

Any idea to solve this problem??

best wishes for 2009
ingmar dl3hby