transmission for bittorrent

[chuck adams]

I've been using transmission under ubuntu 9.04
for bittorrent file transfers.  Running into
an anomaly that I am trying to figure out and
haven't found anything online. 

Here are my observations:

1.  After a period of time the number of seeds and
peers falls off for long transfers.  If I pause the
file transfer and restart then both numbers are
refreshed and both come back with larger values.

2.  If I look at the properties for the files and
then look at the peers I find that there are a 
large number of bittorrent connections using
uTorrent 1.8.2 that have a status download of 'd'
instead of 'D', which means that I could download
from the peer/seeder if they allowed it.

If I go to my old kubuntu 8.04 system and fire up
ktorrent, then the same seeder will download to me.
Seems strange.  Since I have 3 days already invested
in one download I don't want to restart on the other
system.  

Anyone have an idea if some port needs to be opened
or parameters modified from the default values for
transmission?  

thanks in advance,

chuck