Too many IDLE in current_query

Dear all,
i'm checking my postgresql server to try to monitoring all activity that are
running.
i run this query:

postgres=# select
current_timestamp - query_start as runtime,
current_query
from pg_stat_activity
order by 1 desc;

and the resul is many rows like this:

runtime | current_query
-------------------------+---------------------------------------------
34 days 06:53:59.959751 | <IDLE>
34 days 06:53:59.924254 | <IDLE>
34 days 06:53:56.870348 | <IDLE>
34 days 06:04:34.553884 | <IDLE>
34 days 06:04:24.975262 | <IDLE>
34 days 06:04:20.951703 | <IDLE>
34 days 06:04:11.200763 | <IDLE>
34 days 02:45:07.633385 | <IDLE>
20 days 06:21:00.519184 | <IDLE>
20 days 04:56:16.008164 | <IDLE>
20 days 04:35:46.465805 | <IDLE>
20 days 01:44:22.723898 | <IDLE>
19 days 07:32:29.484493 | <IDLE>
2 days 09:08:29.955712 | <IDLE>
2 days 09:08:29.929274 | <IDLE>
2 days 09:08:29.914055 | <IDLE>
2 days 09:08:29.910676 | <IDLE>
2 days 09:08:29.231103 | <IDLE>
2 days 09:08:29.22941 | <IDLE>
2 days 09:08:29.20836 | <IDLE>
2 days 09:08:29.203906 | <IDLE>
2 days 09:08:29.198813 | <IDLE>
2 days 09:08:29.19535 | <IDLE>
2 days 09:08:28.214741 | <IDLE>
2 days 09:08:28.210447 | <IDLE>
2 days 09:08:28.183688 | <IDLE>
2 days 09:08:28.179618 | <IDLE>
2 days 09:08:28.161658 | <IDLE>
2 days 09:08:28.151496 | <IDLE>
1 day 09:03:14.978079 | <IDLE>
1 day 09:03:12.246013 | <IDLE>
1 day 08:53:47.763229 | <IDLE>
1 day 08:53:46.744188 | <IDLE>
1 day 08:49:21.584343 | <IDLE>
1 day 07:44:18.245998 | <IDLE>
1 day 05:18:29.171981 | <IDLE>
1 day 03:25:18.260414 | <IDLE>
1 day 02:47:34.402538 | <IDLE>
1 day 02:47:33.816568 | <IDLE>
1 day 02:47:33.472902 | <IDLE>
1 day 00:59:58.531684 | <IDLE>
07:07:43.146363 | <IDLE>
06:52:19.014704 | <IDLE>
...
...

i know that this is just a snapshot of the situation of the server in a
particular moment, so i know that i can see all IDLE queries.
The strange thing is that there are quesries that are running from 34 days.I
think is strange.
Do you have any suggestions? My postgresql version is 8.4. I know that in
postgresql 9.0 i can see also application_name filed.
Thanks for your help

Francesco Boccacci