What dabear said. Go into the SCREEN LAYOUT EDITOR and see if anything weird is going on there (ie, is the oil temp widget under the SENSOR button different between the 50% and other layouts. You might try simply deleting the nonworking one and then re-adding it.
Also, before changing anything, perform a settings backup in case you want to get back to the original state, or if you want, send that file to support at dynonavionics dot com and we can take a look at what's going on in that file too.