P2P azureus degrades LAN performance, Vista 32/64

Hello,

New here, so please bear with me.

I have a simple setup at home:

1. ADSL Router/Speedtouch, 24mbit ADSL,DHCP connected to
2. Switch, SMC - gigabit with jumboframes
3. Cat6 cables

When I start all computers clean, I can transfer files more or less at the speed of the harddrives ( about 55mb/sec to the laptops and about 75-85mb/sec to the workstations) - great!

If I however use Azureus for a while - performance goes down to maybe 25mb/sec(even if I have closed azureus). Sometimes I can "fix" it by power off the switch and router, but oftenly I have to:

netsh int ip reset reset.log
netsh winsock reset catalog
reboot!

To get it back to a 100% again, is this normal? Can I somehow avoid this? My switch is "dumb", should I benefit from having a Smart-switch?

I running Vista 64 and 32 bit with SP1, and I do have the latest drivers and updates in place.

Please advice!

best regards,

Lazze Z

Stockholm, Sweden