I have jut started having the exact same problem as this!
I haven't formatted the phone yet - not sure what settings/data I'll lose if I do this so I'm a little nervous about doing it.
I put my phone on silent overnight a couple of nights ago and when I changed the profile back to the general one (or indeed any other profile) the next morning I found that I wasn't getting SMS notifications. I didn't change any settings at all apart from switch between two profiles.
Before I used to get a tone, a message on the screen saying 1 new message, an envelope in the top right corner and if the phone was on the screensaver it would have an envelope and a number just under the time bar.
Now I get no tone or on-screen message, if I choose a profile that is supposed to vibrate I also get no vibrate. All I get is the little envelope that appears in the top right of the screen.
When the screensaver is on I sometimes get the envelope on there, but more often than not I don't get that either.
Also (and I don't know if this is related or a co-incidence) occasionally when I reply to an SMS the screen just flickers and appears to stay on the original (no compose screen appears) but when I look in Drafts there is a blank message with no recipient - however I cannot view, edit or delete this message (I now have 3 of them in there).
I was using the MMC as my SMS memory. I have just switched to the phone memory to see if that helps at all, but haven't received an SMS yet to test it.
If anyone else has had this problem and knows how to fix it please please help!
Thanks - wend