was your file started in an 8.0.x release of archiCAD? these were all issues that cropped up every now and then for me in those bad old days.
try merging your existing file into a 'new and reset' 8.1v2 file, or better still, try eric batte's 'forward merge' tip:
http://archicad-talk.graphisoft.com/viewtopic.php?p=4893#4893
this will hopefully have the effect of cleaning out bad attributes left over from early versions of archiCAD 8.
HTH
~/archiben
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