Set conditional breakpoint when debugging with CBD in QtCreator

I found that I am not able to set a conditional breakpoint when I compile my program with MSVC2008 and debug it with CDB inside QtCreator

After a debugging session starts, I tried to add a breakpoint and edit it in the breakpoint editing dialog, the condition field is greyed out.

I could set the condition field before the debugging session starts. But it seems the condition is totally ignored duing the session.

Conditional breakpoint works all right when I compile with mingw and debug with GDB.

Any idea? Is this a known bug?