Vista - lost my upload speed 3 weeks ago and isp cant tell me why

i have a msi Motherboard with a amd dual core 6000 hypr link , a 9500 gt evga 1 gb pci exspress card and a nvidia 10/100/100 net driver (all drivers are current and upto date i am very positive about that )
about 3 weeks ago my upload speed went from 170 kbs down to 106 kbs i have a 2wire 38000 hgv-b adsl modem with a lan line connection and a 18 MB connection threw At&T Uverse and they cant figure out what the problem is
they have tested the line and replaced the modem 2 times in the last 2 weeks
ive tested the connection on every speed test there is on the net and they all come back with the same results
according to the config on the modem i have
• Incoming: 25216 kbps
outgoing : 2024 kbps

now speed test results are this
down speed :2031 KBps
up speed : 107 KBps
3 weeks ago the up speed was at 175 - 180 KBs

the down speed is fine i hit well over 1.3 Mbps and the up speed is whats the problem seeing as i own a shoutcast server radio station and was able to send up 124 KBs and still get almost a 1 MBps down speed
now i cant even go over 56 kbs up or i wont be able to use the internet or it will be realy realy slow
im just woundering if a 18 MB connection from Uverse is the problem or if i did something ,or if this seems like a isp lie in speed and should tell them to go F@ck themselfs and find a new isp
any ideas or help would be much appreciated

I had exactly the same problem. Turned out to be the nVidia network configuration. From your Control Panel, open the NVIDIA Control Panel. Under network settings see if "Enable First Packet" is checked. It may well be as that is the recommended configuration. Change the configuration to Disable FirstPacket and see if it helps. It dramatically improved uploads from my computer to a local network server. I can now upload in a couple of seconds what took 5 minutes before.

thank you it helped im in the middle of dling a new nvidia network driver maybe that will bring me back up to full speed im up to about 160kbps now which is a big difference than 99kbps