I've been dealing with this issue for a while, but it just frustrated me this morning when I lost a rather large geeklist item:
Sporadically when using Chrome replies to threads will be completely deleted when I click "Submit". Typically a thick blue bar will appear where the new reply should be, and no amount of hitting the "Back" button or cursing will get me my reply's text back.
I've taken to usually copying replies before I click submit so that if the error happens I can re-reply with pasted text. Usually on the second try my replies go through without a problem.
With new posts clicking submit will merely time-out & everything will be lost. For instance, it just did this with this very post & I got the chance to add this paragraph. (Fortunately I copied the post before submitting)