WinCC flexible 2005 won't exit RT on MP 277 via Profibus

Hi!

Have a project with the following.

1 CPU 315F-2 PN/DP (Station Address 2)
1 MP 277 8" TOUCH (Station Address 3)
1 OP 73 (Station Address 1)

When downloading project to the MP 277 I manually have to exit RT.
That insn't necessary when I download to the OP 73. Siemens says it
should be possible. When using Ethernet the RT exit automagically. But
that isn't possible to use in the field when commissioning.

Using WinCC flexible 2005 SP1

Regards

    -- Daniel