Error while dropping a table

Howdy:

Running PostgreSQL 7.1.3 on RedHat Linux 2.4.7-10.

I'm doing a bit of housecleaning and after dropping a table,
I get this error:

[snip error]

testdb=> drop table db2_se_2002;
NOTICE:  RegisterSharedInvalid: SI buffer overflow
DROP
testdb=>

[/snip error]

I've never seen this before.  What does it mean?
Should I be concerned?

Thanks!

-X