single-pages with paramters are blank since upgrade 5.4.2

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I have a package made by myself (it's named "dbee") that uses single-pages under dashboard for managing purposes. Some of the pages use parameters passed through the URL (I don't know how it's called...), i.e: the basic single page has the following url:
http://.../dashboard/dbee/database...
Some functions are called with the same url followed by a parameter separated with the slash (like it was a path), i.e.:
http://.../dashboard/dbee/database/pkDbeeContact...
This parameter is passed to the view() function in the controller of the single page "database".
Now, until v5.4.1.1 everything worked perfect. But since the update to 5.4.2 (and later to 5.4.2.1), if the page is called with the parameter, c5 passes an empty page (only html, header and body tags). All the functions in the controller are proceeded correctly, but not so the single-page. If the page is called without parameter, everything is working well.
Has anybody a hint for me to locate this problem? Are there known changes in the version upgrade affecting this parameter thing?

cgrauer