I've tried the trial version of the application, it seems to be a problem with Wine's uniscribe implementation. If you own Windows Vista or Seven, you can try overriding usp10.dll in Wine by copying the native usp10.dll into Wine's /system32 directory, and setting it to native in winecfg. I have only Win Xp installed, which comes with an older version of usp10.dll (1.420.2600.5512). The readability of text in the application has been definitely improved but it was still not perfect. Uniscribe support is constantly improving in Wine, please file a bug in Bugzilla.
