Unable to connect through HTTP proxy

[Yashgt]

Hi,

I am not able to get past my HTTP proxy for my Yahoo account
configured in Pdgin 2.4.2 on Win XP. My standalone Yahoo messenger
works fine. Yahoo is currently the only account I have added to
Pidgin.

I get the follwoing errors:
(11:44:38) proxy: Connecting to scs.msg.yahoo.com:5050 via
myproxy.mycompany.co.in:8080 using HTTP
(11:44:38) proxy: Connection in progress
(11:44:38) proxy: Connected to scs.msg.yahoo.com:5050.
(11:44:38) proxy: Using CONNECT tunneling for scs.msg.yahoo.com:5050
(11:44:38) proxy: Proxy server replied with:
HTTP/1.1 407 Proxy Authentication Required ( The ISA Server requires
authorization to fulfill the request. Access to the Web Proxy filter
is denied.  )

Via: 1.1 GOLDSTEIN

Proxy-Authenticate: Negotiate

Proxy-Authenticate: Kerberos

Proxy-Authenticate: NTLM

Proxy-Authenticate: Basic realm="goldstein.mycompany.co.in"

Connection: close

Proxy-Connection: close

Pragma: no-cache

Cache-Control: no-cache

Content-Type: text/html

Content-Length: 721
(11:44:38) proxy: Connection attempt failed: HTTP proxy connection
error 407
(11:44:39) account: Disconnecting account 00C36630
(11:44:39) connection: Disconnecting connection 0187F5F8
(11:44:39) connection: Destroying connection 0187F5F8

Can someone help me resolve this issue? I have configure the correct
username and password for the HTTP proxy.

I am able to connect from home when I do not use HTTP proxy.

Thanks,
Yash