desk.cpl exits slowly on WinXPSP3

Reproduction steps:

• Startup our desk.cpl on Windows XPSP3
• Click "OK" to immediately end it again

Expected result:
If I do that with MS WinXPSP3 desk.cpl it closes without any noticable delay when clicking OK

Observed result
If I do the same with our desk.cpl from 0.4.15-dev-8609-g07abea9 GCC8.4.0dbg built from RosBE2.2.2 on WinXPSP3
it shows an hourglass for about 1second before it finally closes

It is clear, that the inefficiency is compiled into the desk.cpl binary.