Apple has received reports of users having difficulty printing from Mac OS 8.5 to their fax-capable LaserWriters. Present workarounds include using the 8.2.3f driver for faxing only, and the LaserWriter 8.6 driver or later for printing.
Another solution is to use LaserWriter 8.3.4, which can be downloaded from Apple Software Updates sites. It supports printing and faxing, but does not contain any of the fax extras such as the address book.
This article can help you locate the software update mentioned here: