I've worked a number of Intermec scanner cases. Like VoIP, telnet based apps
are very time sensitive, have problems with dropped/lost packets, etc. You may
find that WPA2-PSK (use AES, not auto) works best if you do roam between APs
with L2 cached credentials. You might also disable background scanning after
your APs are on assumed best channels, as channel changes also disrupt telnet
applications. Run the latest ZD firmware 220.127.116.11.15, and open a ticket with support
if you need deeper troubleshooting. Latest firmware/drivers on Intmec are equally
as important, as I don't think you should have occasional ping timeouts.