A problem with the omnimeter

[in_vino_vomitus]

So. I recently enabled map contacts, which makes determining course and speed ridiculously easy. I'd like to turn them off again. Especially since I've been itching to use the omnimeter that's part of the OTC mod. However, for some reason, the sliding scales seem to be cut in half. I thought this might be an issue with screen resolution, but everything I've tried so far yields the same result. Can anyone help?

I wasn't sure if this would be a better query for a PM, but on balance I thought if someone else has the same problem then an answer here would be useful to them also - and if anyone else has had this problem and fixed it, I don't mind where the solution comes from

finally a word of thanks to Cap'n Scurvy for the work he's put into this mod. If I could buy you a beer for it, I would do....