Why not just multi log and trade everything over??? Either way there is no way that's possible. You can;t patch something like this, I know because I recently did it.
Actually I experienced the same thing, I just lost 1 coin though because I wanted to test it out first.
It would be waaaaay too much effort to implement an IP-based drop trading barrier, but something stopped the items from showing. Perhaps dropped items disappear when you log out for more than a minute?
What I've been doing is setting stuff on a table, then logging out and grabbing off the table on my other account. Just did this a day or two ago and it worked fine.