Function call at address in ROM

[lpcware]

Content originally posted in LPCWare by Loop on Thu Sep 27 05:24:31 MST 2012
Hey,

I need to call a function over a known address(0x40000) in ROM. My solution is working without troubles.
But when I debug the system and want to upload new code I always get a ET:Flash driver not ready message.
After restart(Ends up in the HardFault_Handler) I can write on the Flash again.

    Bool8 (*UnknownGetFunctions)(ttag_RTOSFunctions*);
    uInt32* uiUnknownInterfaceAddressPointer = (uInt32 *)0x40000;
    UnknownGetFunctions = (void*)*uiUnknownInterfaceAddressPointer; //*address; //0x7ccc0;

    ttag_RTOSFunctions ptagRTOSFunctions;

    UnknownGetFunctions(&ptagRTOSFunctions);

So is there a problem in my code, or does the debugger have troubles understanding the call of my function?