I beleive I have fixed the problem with Palm OS 5 devices and Perfect Remote. This has been tested on NX73 and NZ90 and should be good for all Clié OS4 and OS5 devices with Enhanced IR Ports (thoose that come with Sony's Remote Commander Application).
For those of you who don't know, Perfect Remote is software that allows you to run Philips Pronto configuration files (CCF's) on your Clié device.
Visit my web site for details: [Link: geocities.com]
Please let me know if your Clié model now works!