While I've never used the internal modem myself, and probably never will, I have received confirmation from "rv" <herve add-at-sign-here hawaii dot edu> that the modem does work with version 2.9.2 (and presumably later) of the smartlink driver.

The following sites might also be interesting: First of all, the Linmodems homepage which, among other things, hosts the Smartlink driver. Secondly, the Unofficial PCTel Winmodem website seems to give the modem two thumbs up. There are also some other end user reports here and here that seems to report success on similar modems after some efforts.