[Wine] Windows-Application can't handle .dbf- Files correctly

[BTL]

For several days, I try to run an Windows- Application on an Ubuntu 7.04 System through wine 0.9.58.
In detail, it's a tool for supporting a change of food and sports behavior.

The tool is freeware, named "Diät- Tagebuch" (diet diary or diet day book) and downloadable at: http://www.diet-daybook.de/DTBInstall2.exe
(unfortunately it's only in german)

 The DTBInstall2.exe is an self- extracting archive containing some dBase- files and the exe. No installation is needed.

The application starts without problems and the GUI seems to be useable. 
In the upper left corner you can manipulate the current date and in the upper right corner you can enter your daily weight. 
Those data should be consolidated in the file DTB_DTB.dbf. But that seems to make problems with wine. (I tested the application with WinXP and it seems to work fine there.)

The current day- weight isn't written in the same row as the date, but it is written in a new one at the end of the file. 

Obviously wine causes a problem adding Data into an predetermined dataset/table row.

Is there any idea how to run this tool probably in wine or fix the dBase- issue?