not sure it's of any help, but...
We had a similar problem with a slave printer exhibiting different  
behaviour over telnet and vt. It wasn't a big issue, and I had decided  
the telnet-implementation was buggy. But as more users started to use  
telnet instead of NS/VT, I figured we should do something - it turned  
out (i.e. HPRC told me) we had got away with sloppy coding, that didn't  
work over telnet. iirc the details were we couldn't use FCONTROL/FWRITE  
to the printer unless surrounded by VTRURNOFF / VTURNON, something that  
NS/VT didn't mind...
... as stated, not sure it's of help (i can dig up more details), but  
it shows that telnet differs, and maybe you should check that your  
vplus-code is in accordance with the 'books'

/per
---------------------------------------------------
Per Ostberg  / [log in to unmask]
phone +46-8-58581213 / fax +46-8-58587710
Huddinge University Hospital
LabMedicin-IT / C1 74 / S-141 86  HUDDINGE / SWEDEN
---------------------------------------------------
> -----Ursprungligt meddelande-----
> Från: epj.chamba.nospam /shar [mailto:[log in to unmask]]
> Skickat: den 28 september 2000 22:01
> Till: HP3000-L /shar
> Kopia: epj.chamba.nospam /shar
> Ämne: [HP3000-L] Vplus error on telnet connection
>  
>  
> We recently enabled telnet access to ours HP3000 with MPE/iX  
> 6.x (can't
> remember the exact patch level but can find it if relevant).
>  
> The intrinsic vcloseterm fails with all the programs we  
> wrote. It returns a
> value of 10 for v-status (corresponding message is "the terminal close
> failed"). But does not fail with HP programs using vplus, like Nmmgr.
>  
> Everything is ok with DTC and NS/VT connections ...  I  
> suspect something
> wrong in the form files ... did someone encounter a similar problem ?
>  
> Eric Chamba
>