I am on my third WMR-968 Anemometer. It seems that some sort of electrical malfunction occurs on them about every 1.5 years (at least for me) I have tried swapping units sensor units and transmitter. One time it was the sensor or the Anemometer itself, the other time it was both units. I have the mast grounded well, and even clean the unit every few months. I am under the opinion that the electronics in the units are very sensitive to static discharge even though it is well grounded. I have had to bite the bullet, and purchased a new setup twice now, to keep my website going. I am considering switching over to a new name brand and weather station sometime in the summer months.
But the lowest price for new units that I was able to find is Ambient's website, but you can purchase them together, saving a few dollars.
http://www.ambientweather.com/wmwmwmanwtr.html