Background label (filled out rectangle) in 1.8.0 was calculated separately for every line,
Now in 1.8.1 weight of background label is taken just as longest weight from all lines (not separately)

so for sysmap element:

somelabel
SomeLongeeeeeeeerPartOfLabel_line
Info_line

The entire background is as long as longest line.. If info_line is not "OK" but problem(Trigger name or sum of problem).. the line is really really long.. so it covers other thins, imported things..
If someone REALLY use maps.. it's a BIG problem ((