2013-05-04 Admin note: the instructions below are very old and may not be applicable to current Wine. 

This is only intended for people who know how to apply patches and how to compile from source

Currently you need to apply the following patches on top of wine 0.9.41:
ntdll: NtAreMappedFilesTheSame semi stub
ntdll: call NtAreMappedFilesTheSame to guard against duplicated loading of the same dll
dsound: zero out parameters even in case of a error (this might not be needed for newer versions of joost)

Select a virtual desktop with the size of 800x600, else the picture is shifted to the bottom.
Cd into the Joost directory then run wine xulrunner/tvprunner.exe application.ini
You won't be able to exit the client cleanly as the icon in the notification area does not seem to react to mouse clicks when in virtual desktop mode,
so you need to enter you account name and password every time running joost.

Tested with patches applied to git version wine-0.9.41-63-g96937e0 (17.07.2007)