ORIGINAL: ats909
I guess there may be some risks with early 14mzs (for example, less than 3000 ?) .
If your 14mz's number is less than 3k, I suggest you to check it by process mentioned above.
As Steve Kaluf tried to tell you earlier, this is almost positively a sign that one or more of your stick pots are going bad. It is NOT a problem with all radios, or radios with certain serial numbers. When the pots wear they can start to show this behavior.
You need to send your TX into your nearest service center to have it checked over.
You should be able to find the one closest to you on this list:
http://www.futaba-rc.com/futdist.html