Whats Up With The Treeview Posting Configuration?

[Hack]

Check you "Display Mode" in the upper right hand side of the page. You get three options for viewing a thread.
Linear/Threaded/Hybrid. Make sure you have yours on linear to retain the original display setting.

I found out about the "Display Mode" thing by accident one time because my display was exactly the way SeanK described. I know for a fact that I didn't change it because at that point, I didn't even know you could change it. But by mucking about for a while, I figured out how to change it back.

Since then it happened one other time as well.

I'm just wondering if anyone else has experienced the display mode just sort of 'changing itself'?