Moudir,

Sorry I was so busy the last few days and didn't check the new posts.

As for your question (Is that normal for all housing leases in Qatar? You sign with the agent, and issue the cheques to the owner?)
No this is not normal, but some owners don't have the tenant form so they ask any agent to do it for them but it will be signed by the owner and the tenant and ofcourse the cheques will be issued to the owner.

Moudir, I didn't understand what did you mean by "may be he's having a siesta, but watch his sidekick, specially if his not so swift.", is it a sort of a language between you guys that we don't know about?

Ayman