Sounds like a bug, but it could be a connection issue. If it's a connection issue log out and back in and it should show up I believe, I'd ticket it or post in the support forums, I've seen them refund Cr. To people that expeirience bugs if they can verify it, so it's worth a shot.
Bug going around it seems, it's hit quite a few people inlcuding me. A mod really needs to sticky a thread telling people to not buy/sell cargo at the moment and wait until tomorrow when FD have woken up.