flipalong have you done is using your mac i am havn reall issues....

today i started having the problem too. for some reason with one particular contact the messages show when they are new, but then disappear. i can read them from the window when they pop up and are new. but once i close the convo, it cannot be found again. it does not add to the conversations list. the persons name is completely not there in conversations. not even the sms from before the problem. only an entry with a blank name shows at the top of conversations with the most recent message preview from that person. when i click it, an empty window called "SMS - ____" appears but never loads anything. all subsequent messages from this person come in, cause beeps, but never appear. i have to constantly reboot to get a new message that hasnt come in yet from that person. i tried deleting / clearing the convo, but that doesnt fix it. a few hours ago i was having a conversation with the person when my phone died. i wonder if the phone dying caused the database to get corrupted for entries with that person? i will try the two suggestions i saw here for fixing the problem without reflashing. thanks guys. good luck to esther. (i think this is a good example of why the n900 isnt a mass market phone, but more of an enthusiasts phone)

Right, first of all, what in gods name possessed you to buy a mac?!

Don't feed Steve 'hand' Jobs crack addiction, your as bad as those bastards that feed the pigeons at train stations!

Secondly, open conversations, click the top menu and click delete conversations, then press ctrl a, hit delete and restart your phone.

This should rebuild the database.

If that doesn't work let me know and I'll help you through removing and re-creating it. You really are over thinking things, it's easier than you're making it, I promise.

Which ways have you tried? And maybe more importantly, what happened?

If you followed my or mixed_man's instructions, your database should be erased (that means that all your messages should be gone, is that what happened? If not, probably something went wrong) If your database is erased, reboot your phone (or recreate the file manully with the command touch /home/user/.rtcom-eventlogger/el.db). If you can receive new messages now, it's ok.
And if you succesfully reflashed, it should be ok too.

Anyway, maybe the easiest thing to do is to return the phone to the store or a Nokia Service Point... they will (hopefully) fix it for you