hey mate, Since sending it to GM for an upgrade to V8 (just before I sold it) I only used it a couple of times..
My suggestion to you would be to hold the set button untill it beeps 3 times quickly and once for a long time.. that will do a factory reset on the speedo, power it off.. then power it on again. - holding the set button again should allow you to access the menu system,
this forum (whilst in german)
http://forum.gm-racing.de/forum/foru...us-regler.aspx
has lots of useful information, particularly if you use babel fish to translate the german post's to english.
Hope this helps!
Matt