There are known problems with the earlier inetds, and with Reflection
5.2 (which is what we are using, too), so you might want to eval the
newest version. We have always been on MPE 55, so I cannot address 50,
except to say that according to what I have read, inetd has changed
substantially since its initial release in 50. WRQ strongly recommends
connecting with NS/VT. If you really really want to use telnet, check
out AICS's QCTerm, and see how that works for you. I just downloaded it
recently, and am favorably impressed with it.

When your session deactivates, does the Reflection title bar show the
active title bar color, or the inactive title bar color? I have had
oddities where one of the dozen things I am running while take Windows
focus away from my current screen. Have you been able to see if the
session hangs in the sense that everything stops, or does activity
continue?

You might want to give the following a try; it sustains a conversation
of several exchanges between the client and the host. WRQ Tech support
sent me a script to test with, which I have adapted to my tastes. Any
poor design is my own. I connect via telnet, open this RCL, and run it.
You will of course need to replace 'MPE:' with whatever your system
prompt is, and change the counter to taste. Also, I hold for one second,
because holding for just the prompt was consuming 20% of the CPU. Here
is the text:

let v1 = 0
:begin
if v1 > 999
 display " I just did this $1 times"
 goto stop
else
 let v1 = v1 + 1
 display "Iteration #$1 ^M^J"
 transmit "SHOWME^M^J"
 hold for "MPE:"
 transmit "SHOWTIME^M^J"
 hold 0:0:1
 goto begin
endif
:stop
stop