problems with map after upgrade 1.6 to 1.8.1

[yves_69]

hello,
after upgrade, I've got 2 principal problems with maps:
1. Configuration:
No text/ only icons in map configuration screen (cf image 2)
2. Display map:
the text "Unknown" is still here, though I disactivate the items, and triggers for hosts that were disactivated.
Notice th error "unidefined offset" in the bottom .
thanks for your help
yves
centos 5.3/ php 5.1.6/ mysql 5.0.77

[yves_69]

another information

When I delete all disactivated hosts for a group , the group status becomes "OK" on the displayed map (and not "unknown" )
yves