While mining, when you are viewing the inventory screen and looking at what you have stored around the stations, when the mining process restarts and the ore is added to your cargo the inventory is reset. Basically, if you have drilled down a couple of levels, the inventory is reset so you have to drill down again.

Would it be possible for the inventory tree to stay as it is while you are looking at it?

and ... this has the annoying side effect that, if you have a large inventory, it takes longer to update the list than it takes to mine a unit, which causes the game to freeze up till the ship is full. Which can take quite a while if you are mining in a moth.

I think I've complained about that before. :P

EDIT: yes I did! http://www.vendetta-online.com/x/msgboard/2/14915#187698

you know what? I wonder if this is related to the growing framerate loss the longer you mine/bot...

Hmm, framerate still drops over time? blargh. I'll make a note of it.