More likely a bad connection in the vertical.  Between the joints or 
maybe where the coax connects, or perhaps something in the 
grounding.  Do you have a dummy load you could put on the antenna 
side of the versatuner to see if everything inside is stable?
Antenna problems are fun.  Good luck.
Pat, K9JAUAt 10:38 AM 9/22/2009, you wrote:
>Hi list.
>I have an SWR problem.
>Let me describe my set up first.
>I am using A Kenwood TS-430 going into a Heathkit SB-220.
>The SB-220 goes into my TW-1 Talking meter.
>The meter goes into my MFJ versa tuner, and the tuner goes into A Cushcraft
>R7.
>I can Tune the SWR down to 1.0 to 1, wait 5 minutes and it's up to 2.9 to 1.
>Wait another 5 minutes and it's down to something like 1.4 to 1.
>All with out changing anything.
>Could it be bad coax?
>It really gets bad when it gets windy.
>Thanks in advance for any help.