new telnet problem

[leisuretime]

I've been running a TS server for over a year with only occasional hiccups, all of which were solved by reading here. This morning, I wanted to add a channel, so I tried to find the telnet command (I know, there isn't one) so I then tried to load the admin page which didn't work. Again, I turned to the trusty forum, and tried all the suggestions to login: <internal IP>, <external IP> and <localhost>, all failed... except... the simplest of suggestions; shut down TS and re-run. Presto, my admin page works fine now. I'm still not sure why, but I digress...

Now, I can no longer access TS with telnet. Grrrr. I tried everyway that I can think of:

Same PC as TS with Putty:
67.171.164.xxx:51234 (no [TS] prompt, aborts after <cr>)**
192.168.0.101:51234 (no [TS] prompt, aborts after <cr>)
localhost:51234 (no [TS] prompt, aborts after <cr>)

**this was my pre-defined template for Putty that always worked before.

Same PC as TS with mstelnet:
open 67.171.164.xxx:51234 (no response, connect failed)
open 192.168.0.101:51234 (no response, connect failed)
open localhost:51234 (no response, connect failed)

Another PC on the same network
67.171.164.xxx:51234 (no response, connect failed)
192.168.0.101:51234 (no response, connect failed)

All I did was shut down TS and re-run it. Of course, I have rebooted several times trying to troubleshoot this, but no joy. Clients can still connect, both from the same network and the internet. Putty always connected me before, with no problems. It must be something simple, but I can't see it... what am I missing??

[edit: I lost the first post, forgot to include config info when I rewrote it:
TS is running on Win2k, is the only external app running, PC is in DMZ zone of DI614+ router, (although none of that has changed in at least 3 months).]

Thanks in advance for any suggestions.