All ops on one particular table cause a hang?

I just created a table, but now cannot access it or even drop it. I can
access all the other tables in the database just fine. But any client
command or app (like pg_dumpall) that references this new table hang.

I looked through the docs and FAQ for a any mention of this, or a way to
repair or drop a table some other way, but can't find it.

Thanks for any ideas.
Robb