[ltp] PCMCIA modem go-slow

[cr]

I'm still having troubles with my Thinkpad modem 
(Thinkpad i1200,   Xircom CM-56G modem)

The modem works fine under Win98.

Under Woody (with the i82365 driver module) and Sarge (with the yenta 
module), it works fine on the _very_ few occasions when it actually manages 
to dial my ISP. 

Usually, using KPPP, instead of returning 'OK' in the log window or whatever 
is expected, it returns individual letters from its ID string incredibly 
slowly (e.g. 'Xircom CreditCard GlobalACCESS ' etc), or sometimes the setup 
string (ATM1L1 etc).
KPPP's 'Query Modem' shows letters from its ID string in registers ATI to 
ATI7.
Typing 'ATDT086755666' (my ISP's number) into the KPPP mini-terminal makes it 
dial correctly (I can hear the call going through) but only echoes garbage to 
the screen.

I tried other front-ends:
Xisp  returns part of the modem ID string, reports modem init failed
Gnome-ppp (which uses wv-dial) returns 'Modem not responding'

Minicom dials through OK

I've been right through the PCMCIA HOWTO, checked for IRQ clashes -  
typically, test_modem  reports  "IRQ3 delivery problem"  but on running it a 
second time, it reports "IRQ3 OK"
Same happens if I exclude IRQ3 in /etc/pcmcia/config.opts and force it to use 
another IRQ.

I do notice that  test_setup  reports that yenta is using IRQ10 and port 
0x02b8, which is different from what the modem on /dev/ttyS3 is using (IRQ3 
and 0x02e8).   I don't know if this is what should happen or not.

The CM-56G is not listed in the Linux compatibility list; other very similar 
Xircoms are (and besides, _when_ it dials through, it works perfectly 
thereafter).   

Can anyone suggest a further line of investigation?

cr