Yes, it just happened to me. It also happened once before about 1 month ago and it was the same person. All our text messages are gone! Although the last time it happened, for some reason they reappeared a couple of hours later. I don't get it!
I think the only limit would be the phone's memory. I have read in these forums where people have thousands and thousands of text messages. It should not delete them unless the phone is low on memory. If not it is for sure a glitch in the system.