Arrived into YUL from IAD this morning on UA. Connecting here on LX to ZRH and BKK. Checked bags were tagged all the way to BKK at IAD.
Somewhat complicated story here:
I decided to clear Canadian immigration and enter Canada to visit the NEXUS office and have my iris scans done (they told me there that I would need an appointment, so that did not happen). So I went back through security and crossed into the international departures pier, "leaving" Canada. This is when I discover that the international pier at YUL is basically deserted at mid-morning, and that the MLL won't reopen until 1430. Some security folks were very nice and escorted me back to immigration so I could go through passport control again and re-enter Canada so I could use the domestic MLL. A friendly suggestion from the CBSA Agent at passport control led me to check at the baggage office to see if my bags actually were checked through. Lo and behold, there are my bags waiting for me.
So I grab my bags and head through customs, and back up to the check-in desks at the landside. Since my connecting flight isn't for several hours, the LX desks aren't open yet. So rather than sitting in the MLL (international or domestic), I'm sitting on a bench at the landside with my checked bags, waiting for LX to open check-in. While very polite, the AC check-in staff assured me that they are not contracted to handle LX check-in and that I would have to wait for them to arrive.

This is not the smoothest connection I've ever had.