ARM Cortex M3 STM32F207 processor hangs during the initializing if the code-size is more then 64k

Hallo,

I'm using a ARM Cortex M3 STM32F207 processor and if the code of  my project becomes a value of more than 64k, the processor hangs before the PC reach the __main().

The code starts at 0x08020000 (sector 5) and hangs at a Breakpoint or any like that --> 0x08020ECE BEAB     Bkt 0xAB

Should I use any compiler/linker option for code more than 64k, or has anybody an idea what's my mistake?

Thank's