PgAdmin III 1.12 crazy memory usage

I can't recreate this, so it may not be much help, but I left PgAdmin
running with no query windows open at all, and eventually I noticed my
PC slowing right down as memory started to swap.  I've attached a
screenshot to show its memory usage.

Actions I had performed earlier are attempting to select all rows from
a massive table, and closed that result window a few seconds into it
attempting to fetch results.  I had issued a few queries in other
query windows which were quite minor ones which got counts.  I doubled
the tablespace's random page cost for one of the connected clusters,
and updated the statistics target for a column on a table, then
performed a VACUUM ANALYZE.  And I also attempted to restore a ~20GB
custom format database into a new database, but killed the process
some minutes into it as the cancel button on the restore window wasn't
responding.  The window then showed a status of restore failed.  I
then deleted that database.

After all this, no more query windows, result windows, or any other
PgAdmin-related windows were open except for the main application.  It
was presumably idle as I had no other running processes, and was left
focused on a cluster node.

--
Thom Brown
Twitter: @darkixion
IRC (freenode): dark_ixion
Registered Linux user: #516935