In case you wondering, the Windows Mobile Lotus Traveler 8.0.1.2 client works with Traveler 8.5 server.
When I was looking for this info last week I couldn’t find any so I did some testing last weekend.
http://woonjas.linuxnerd.org/web/woonblog.nsf/d6plinks/NWEA-7PRCSW
If your device running the 8.5 client stops synchronizing after implementing security settings in the Traveler policy settings document, just downgrade to the 8.0.1.x client which happily ignores these security settings 
Cheers.
(IRC: Woonjas on EFNet’s notes)