Hi. I have become very informed in this area. In fact it has become one of my goals to solve this problem. I created a project to solve this problem (
http://zsrep.sourceforge.net).
It is not TrollTech's problem. Qtopia and Qtopia Desktop that are released by TrollTech use the XML method of storing PIM data and synchronize using an FTP based method. Sharp used this method of synchronizing on the Zaurus SL-5500 ROMs below 3.10.
When, Sharp released the Zaurus SL-5600 ROM 1.0 and SL-5500 ROM 3.10 they switched to a new method of PIM data storage which they call DTM. They also to the TrollTech version of Qtopia and modified it for a different method of synchronization. They also took a copy of Qtopia Desktop from TrollTech and modified it to work with this new method of synchronization. This new method of synchronization is also used on the SL-6000. Sharp has refused to release the sync protocol specs to me and has not given me the modified code. Sharp it seems did not make their modifications platform independent as the orig Qtopia Desktop was, hence, there is no Linux version of the Sharp modified Qtopia Desktop.
Due to the adove I started the ZSREP (Zaurus Synchronization Reverse Engineering Project), a project in which I reverse engineer the sync protocol to provide a Linux method for synchronizing a Zaurus using the new ROMs. I currently know enough to obtain the data items that need to be synced from the zaurus and am very very very close to being able to flawlessly put data onto the zaurus. The reverse engineering portion of the project is so so close to being finished. Once, that portion is finished I will begin developing a stable application to sync with a chosen desktop PIM tool. We, still need people to test our code and give us results to further reverse engineer the protocol. To find out more about the project please go to
http://zsrep.sourceforge.net.
You can contact me at cyphactor at socal dot rr dot com (cyhactor@socal.rr.com).