Kernel debugger in MP mode causes double fault

Hi folks, has anyone tried to invoke the kernel debugger in a multiprocessor setup? When I boot the demo scenario in qemu with qemu -smp 2 -cpu core2duo and then hit Escape, the system crashes with a double fault. Without smp or with -cpu qemu32 the problem doesn't occur. Can someone confirm this issue or give a hint what could be wrong? Cheers Markus