If it does'nt so with no drives attached then it can't really be the hardware, can it?
So, my question to this would be, does this splitting-thing happen when cold booting and warm booting? Or just on 'warm' booting (i.e. reset by Amiga-Amiga-Control or the reset-switch on the 4kT)?
If the latter is true, then the next question would be, which workbench are you running? 3.1, 3.5, 3.9? The last two have ROM patches which remain in memory at a warm boot. It could be that these patches do funny things with your set-up.
