It seems there's an issue with Temporary objects incorrectly being counted against a parcels available prim count when they are rezzed in world. This would mean that a rez or holo vendor machine that displays a product (temp object) that, together with the regular prims in the area, exceeds the parcel prim allowance, will fail to rez and cause an error message.
Additionally, if all the prims and temp prims in an area total close to the maximum allowed for that area... rezzing an object from inventory whose prim count would put the total over the area's maximum allowed prims CAN result in the item failing to rez, and if the item has restricted permissions might result in the loss of the object permenantly.
I know that not all regions are affected. Mimas has this bug, Imjin does not seem to.
Any idea when someone can look into this and see if this is actually what's happening?