What to do when Ollydbg can't attach to a process?
 

The target is a SafeDisc protected program.
After it runs, I use Ollydbg to attach but can't attach.
What shall I do to make this process attached by Ollydbg?
I guess SafeDisc is something like a debugger that is already debugging the process, so Ollydbg can't attach.
But can I modify something and let the Ollydbg debug the process?
//thanks