Version 18.104.22.168 is a maintenance release and does not include any functionality delivered by Upgrade Pack 1.
A detailed fixlist is now available:
Lotus Notes Traveler 22.214.171.124 includes all APAR fixes up to and including 126.96.36.199 IF1 in addition to the APARs listed here.
Lotus Traveler 188.8.131.52 does not include features delivered in Lotus Traveler 8.5.3 Upgrade Pack 1 and can not be installed on that release. A separate maintenance delivery will be provided for the Upgrade Pack 1 release.