SQL-query takes looong time

postgresql version 8.3.7

When we use "IP Device Info" and enter the name of a SRV the resulting page takes minutes to load. Thanks to the useful Debug:-line at the bottom of the page I know this is because of this query:

SELECT "cam"."camid", "cam"."netboxid", "cam"."sysname", "cam"."ifindex", "cam"."module", "cam"."port", "cam"."start_time", "cam"."end_time", "cam"."misscnt", "cam"."mac" FROM "cam" WHERE "cam"."netboxid" = 566 ORDER BY "cam"."start_time" ASC LIMIT 1

Time: 174.495

The result of this query is 0 lines since this is a SRV and not a GW/GSW. If I drop the "ASC LIMIT 1" from the query I get the answer in no time.

I hope somebody with more SQL-knowledge than me can come up with a fix, since this is quite annoying.

--Ingeborg