I went to check-in for my flight this evening from ATL to LHR, and was unable to do so. It kept asking for a "Permanent Resident Number"--even though it had my passport info, etc. US citizens don't have Permanent Resident Numbers. They told me they are aware of the problem but so far their IT department doesn't seem up to the task of fixing it.

Not a huge deal as I am checking bags, but a minor irritant on my first experience with VS. If I like my Upper Class seat, all will be well. If not, I'll make sure I choose Delta flights in the future.