Change the field 'Is A Building' to 'false' and you will be able to rotate the building. Not sure if setting that field back to 'true after rotation will keep the current rotation or reset it. Sorry.
If you change is a building to false, then rotate it, then turn it to true, it does stay. However... the shadow is off. Looking for a work around, if there is none, i can always lvie without a shadow.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.