all is in the title ;) can't dock anything 

Not really, what is failing...32bit plug-ins, 64bit plug-ins, views. Does the hot spot show when dragging an object to the dock. Is this a single monitor or multi-monitor machine. No problem docking here on a single monitor running 64bit Platinum on Win7, while holding the CTRL key and dragging a 64bit plug-in. Docking also works from the context menu in the upper left corner of a 64bit plug-in window.

holding the CTRL key if you want to dock makes the difference / improvement over X3 where FX when moved around suddenly got docked ...
 
definitely working here ... with FX and synths ...

Dock working fine dual monitors here.

Wookiee
Dock working fine dual monitors here.

 
Same here, and agree with FreeFly Bertl that needing to hold Ctrl is an improvement.

Zo
all is in the title ;) can't dock anything 

Is it possible that your CTRL key is stuck down for some reason....   (I have had that happen on my computer keyboard)

Thks guyz for the usefull answers lol ...i have been so muth on technical test with Platnum that i didn't even knew that docking now is done with Ctrl pressed ...thks , it's working !!

Glad I saw this. Hadn't caught the CTRL key change for docking. Thanks.

It was a good idea for the OP to include "useful" as well as "solved."