This is a bug in eCS (I recently raised a ticket on this) - it's been around a while. If you de-install a card in MPTS that uses Netbios over IP (or, I am guessing NetBEUI), the little popup program comes up and shows no cards supporting TCPBeui and when you click OK it says the config has been updated - unfortunately it doed not remove or Rem out two lines in Config.sys

DEVICE=C:\IBMLAN\NETPROG\RDRHELP.200
and
IFS=C:\IBMLAN\NETPROG\NETWKSTA.200 /I:C:\IBMLAN /N

(I think if you had Netbios also loaded, it wotld probably miss this one as well)
DEVICE=C:\IBMCOM\PROTOCOL\NETBIOS.OS2

The work around is simple - go into config.sys and put rem space at the start of each of these lines.