Buzzing Speedometer?

[Lupo]

There seems to be a buzzing in my speedometer/gauge cluster. It only seems to happen at speeds above 50mph or so. Has anyone else had this problem?
Hopfully a speedo cable change, or greasing. It is really annoying, and I would hate to have to replace my gauge cluster and screw up the ODO.

 

[30footSHO]

Try using a graphite lubricant in the speedo cable. I've read something along these lines on the shotimes FAQ.