Hi,
I once had a similar problem, although my solution won't help in your case I remember that using the following options of the Net::Telnet module helped me a lot in debugging, Just create your object with the following options:

[Output_log => $file,]
[Input_log => $file,]
[download]

This options define a log files that will show you that responses Net::Telnet is working on in the background.
Tell us if it helped :)
Regards,
Leonid M.