Routing problems with 4 Interfaces on Windows 2000 SP4

[sonic]

I use three different www proxy services for three different external lans as follows:
1) on port 79 for navigation on internet via "A" ISP (IF 192.168.1.2)
2) on port 90 for navigation on internet via "B" ISP (IF 192.168.0.2)
3) on port 81 for navigation on extranet (IF 10.78.29.10)
my lan is on IF 90.0.0.1
so when from a client 90.0.0.x I call 90.0.0.1:79 i use "A" ISP, 90.0.0.1:90 "B" ISP and 90.0.0.1:81 i go on extranet.
My problems starts when I enable IF 192.168.0.2 that seems to stop the client navigation also on "A" ISP and on extranet.
What is happening? How can I do?
I am using version 6.2.0.
That is my routing table
=============================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 10.78.29.1 10.78.29.10 1
0.0.0.0 0.0.0.0 192.168.0.1 192.168.0.2 1
0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.2 1
10.78.29.0 255.255.255.0 10.78.29.10 10.78.29.10 1
10.78.29.10 255.255.255.255 127.0.0.1 127.0.0.1 1
10.255.255.255 255.255.255.255 10.78.29.10 10.78.29.10 1
90.0.0.0 255.255.255.0 90.0.0.1 90.0.0.1 1
90.0.0.1 255.255.255.255 127.0.0.1 127.0.0.1 1
90.255.255.255 255.255.255.255 90.0.0.1 90.0.0.1 1
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.0.0 255.255.255.0 192.168.0.2 192.168.0.2 1
192.168.0.2 255.255.255.255 127.0.0.1 127.0.0.1 1
192.168.0.255 255.255.255.255 192.168.0.2 192.168.0.2 1
192.168.1.0 255.255.255.0 192.168.1.2 192.168.1.2 1
192.168.1.2 255.255.255.255 127.0.0.1 127.0.0.1 1
192.168.1.255 255.255.255.255 192.168.1.2 192.168.1.2 1
224.0.0.0 224.0.0.0 10.78.29.10 10.78.29.10 1
224.0.0.0 224.0.0.0 90.0.0.1 90.0.0.1 1
224.0.0.0 224.0.0.0 192.168.0.2 192.168.0.2 1
224.0.0.0 224.0.0.0 192.168.1.2 192.168.1.2 1
255.255.255.255 255.255.255.255 192.168.1.2 192.168.1.2 1
Default Gateway: 192.168.1.1
===========================================================================
Persistent Routes:
None
Thank you.

[jamesc]

investigating issue via support ticket.

[jamesc]

Issue found via instructing to do a tracert -d to each gateway, Sonic found that tracert to 192.168.0.1 replied three times and 30% packet loss via ping command.

Solution ended up being either:
Issue with the autonegation on the network card
Network cable
Port on router