Thanks for getting back to me.
I tried setting "poll_interval=100", and also separately restricting the irq_list to the interrupts reported as unused in /proc/interrupts, and combinations of these, as you suggested in the HOWTO, but my Toshiba 1625 still fails to configure both cards. The first inserted card does okay, but the second one generates "RequestIRQ : Resource in use".
Same problem with Compaq Presario 1925.
With Toshiba 2180CDT, both cards worked after I downloaded the pcmcia3.1.17 version (which is now installed on all three)
Any suggestions would be much appreciated.