[imp] problem sending email

[pratik]

Hie
I have horde-2.0-1, imp-3.0-1, turba-1.0-1 installed on system.When i 
try compose email from imp server it gives me error "The document 
contains no data" this comes when i try it from netscape 7.0 browser & 
the message is sent but same time if i check the same from 
InternetExplorer browser i just get the error page & when i refresh it 
shows me the compose menu page once again but the mail is sent, also 
turba is working fine but m unable to send messages, can any body help 
me what can be the cause of this problem ?
please give me some solution ?? .
Waiting for help

the sight address on which i have installed is

http://mail.vadodaramail.net/horde/

Pratik