There is another bug related to bridges, I noticed it some time ago (well, some years ago or so), mak tested it and found no problem (she never belives me ) but Im quite sure it is there, I've experienced that yesterday with esgaroth. Here we go:
Some times when you click "change bridge path" IWTE does not show all the options it should, like moving doors etc. It only shows the first option (wich I dont remember what is right now), the solution I found for this is clicking "add new bridge", like pretending I would do such, cancel it and then entering the "change bridge..." button again, and then it shows all options correctly.