hi wolfgang et al.,

we found that the new muonbuilder incorrectly calculates the overlap between muons as it includes outlier in the calculation and applies a very strict cut of only one hit overlap. 

as a result we found several close by muons being rejected due to the wrong overlap calculation resulting in inefficiencies. 

the solution to the problem is rather simple, just exclude outliers in the overlap calculation. 

the problem is fixed in:

muoncombinedevaluationtools-00-01-05

as this is a rather nasty bug for groups doing physics analysis, i'd propose
to push for having this tag in for the reprocessing. 
i've already started reprocessing a full run with the tag to ensure that it
does not have any strange side effects. 

we should have results over the weekend.