Try using ethereal or tcpdump to catch the network traffic generated when you connect manually and connect via the script and then compare the output. It should be possible to spot differences relatively easily.

Command line for catching the traffic with tcpdump and dumping it in a file:

tcpdump -w dumpfile host biavl01.baplc.com and port 1344
[download]

You can then view this file with

tcpdump -r dumpfile -xX -s1500
[download]

(Note you need to be root to run the capture)

Another possibility to find out what's going on (which produces output that's easier to parse for humans) is to use the fantastically useful socat and proxy the connection via that. For example:

socat -vv tcp4-listen:4000,reuseaddr,fork tcp4:biavl01.baplc.com:1344
[download]

wil create a proxy between your local host's port 4000 and the remote destination. Now just connect to the local port (via telnet and/or your script) and socat will print out the data transferred.