Strange behavior: row won't delete

HI. I made a small alteration to a table (added a column).

Now when I do:

  vacuum analyze TABLENAME

or

  delete from TABLENAME where id = 99

Nothing happens! The carriage return means the my shell cursor goes to
the next line, but it just stays there. I thought something may be
happening silently but it has been sitting this way since an hour.

How can I debug this? Nothing in the logs at all.