rezzed objects failing to appear

[Airway]

I am having a problem where I rez an object as usual by dragging it from my inventory into my home but the object fails to appear.  I don't see any type of error or message.  The object seems to go missing as it is not in my inventory after I attempt to rez it.  

I have asked the group I rent my skybox from, and they advised me to relog.  This hasn't solved the problem.

I contacted the seller of one of the items that has gone missing but have not yet received a reply.

I have had several items now missing from my inventory for a few days.  I have searched my inventory for these items and also checked my lost items folder, and the items are nowhere to be found.

Are these items gone for good?  Is there a way to get them back?