when removing an item from the "you offer to <user>" side in a private trade, the item appears removed, but sending the trade acts as if the item was not removed from the offer.
this happens whether you remove an entire stack of items, part of a stack of items, or all items from your side of the trade.
also, when i added 5 of an item to a trade, then removed 2, then added 10 again, it created a trade with 15 of that item offered (instead of maybe 13).
the "you want from <user>" side works perfectly fine. (tho the site's buttons to increase or decrease the amount of requested items don't seem to work specifically for the items (not coins) on that side only)
(on that note, did anyone else's private trades just Not work at all the past couple weeks until a few days ago? was that a thing because of the new users?)

There was a front-end bug preventing private trades from working for a while, yes. I made a careless typo in the code that has since been fixed.

Regarding the bug preventing items from being removed: I just checked and it looks like there was another careless typo in the front-end code. I think I must have been severely sleep-deprived when I wrote the private trades system. Anyway, I've fixed this one also; please let me know if you find any other problems!