Odd. All of my posts are there in the My Posts section, going back to my first in 2004. Well over 50. But then, I post on JU - perhaps it's different over on Elemental. Wouldn't think so, but could be.
The forums are so intermingled I'm surprised the settings for the My Posts section would be different from forum to forum. Seems to be the case, however.
Well, I post on JU and WC... maybe this exists in Elementals?
You might try Support...it hurts to lose posts.
Wish I could help more...