Hoop-jumping and other sports

[samuel_z]

I have a stabilized lease. I send my rent checks by registered mail and have return receipts issued, yet my landlord has twice in recent months said he never got the check, and sent me past due notices and caused immense agita. I switched to using postal money orders after the first time, which cost far less to put the inevitable stop-payment on*, but feel like I'm just jumping through hoops for his amusement. It's a nervous aggravation to me, and profitless to the landlord, but it's happening and probably will continue until we meet someday in court. What to do? Whom to call? Suggestions, please.

* NB: Turns out my bank (HSBC) will only stop a check for six months, after which time the check theoretically "expires," though can be made legal tender again with a little manipulating. Find out if your bank does the same; odds are, it does. The only sure way to stop a check is to close the account.