Cannot send private plurks to clique or individuals

It seems me and some of my friends have a problem selecting "send to clique" or sending to an individual friend only? No matter what we do (as in selecting from our list, or typing in the full name of the clique or the individual), the messages go out to the whole world. The option seems to be there, but the messages keep being public. We can, however, send to "only my friends". Thanks for any help you can provide.