Assistant does not refresh cache when .qhc file changes

The problem is that after I recompile my .qhc file and try to load it into Assistant, the old version is still displayed (because it is cached in .../Application Data/... )

It's pretty easy to reproduce,
1) compile a help-file and run the assistant
qcollectiongenerator simpletextviewer.qhcp -o simpletextviewer.qhc
assistant -collectionFile simpletextviewer.qhc
2) change html-file and recompile the help-file and reopen assistant
qcollectiongenerator simpletextviewer.qhcp -o simpletextviewer.qhc
assistant -collectionFile simpletextviewer.qhc
Then the page is opened which has been last opened, but in the old version.
This can be solved by deleting the 'SimpleTextViewer'-folder in '...\Local Settings\Application Data\Trolltech', but this is a very inconvenient solution.

However, this problem does not arise when the assistant is started from within a program (as in the example 'simpletextviewer')
1) compile a help-file and run the program
qcollectiongenerator simpletextviewer.qhcp -o simpletextviewer.qhc
simpletextviewer.exe
2) change html-file and recompile the help-file and reopen assistant
qcollectiongenerator simpletextviewer.qhcp -o simpletextviewer.qhc
simpletextviewer.exe
In this case, the assistant is opened on the page last visited and the page is in the new version, as it should be.

Somehow, it doesn't seem to be the same to call 'assistant' from a command prompt and calling it within a program, using QProcess().start()