MIDI port problem

Hi! I'm testing the demo of Max (4 and 6) on Windows 7 and I'm very happy so far. I want to use Max for controlling and sequencing some MIDI gear and it works fine so far, but now I'm running into some trouble selecting MIDI ports... I can select the ports when the patcher is locked by double-clicking the object, no problem, but what I'd like to do is giving the objects a [port( message like [port a( and so on... In Max 4 it works for all devices like MIDIyoke e.g. except the one of my cheap interface (I'll need a better one soon, but for now it's ok) which would be port k now. If a [port k( message is sent, the object doesn't select it, port a-j work fine.. So, hm, then I tried the current Max and it's even worse because the objects in v6 don't recognize any of the port messages...