They are probably still in the database, they just don't show on a search. I presume you did the search by clicking on your name in a thread. I've done that and it doesn't show all my posts, but I can click on a traced thread on my personal page and be taken to some of my posts that don't come up in a search. I suspect it's related to the database issues that resulted in a lot of problems like the MIDI files not working, double pictures, etc.

I guess all is not completely fixed yet.