New kernel problems...ltmodem

Since upgrading to kernel 2.6.5-7.111 I noticed that my notebook's Lucent winmodem suddenly isn't working. The KInternet log file says that /dev/modem doesn't exist (which it does and is linked to the correct /dev/ttyLT0 device). ltmodem has also been upgraded to 2.6.2-38-8 from 2.6.2-36. If I roll back the change to the kernel and the modem driver the modem works again. Anyone else run into this? Past upgrades haven't broken the link - I wondered if maybe there's a problem with the new ltmodem driver? Cheers, cm