When I want to "place" an image from Bridge to Photoshop, the menu command is greyed out.
Do you have Photoshop in the menu Tools (at the bottom) and can you see the commands in there?
Check if you have the start up script selected or if it is there at all. (Bridge Preferences Start Up script).
If deselected select it again, otherwise restart Bridge holding down option key (control for windows) while restarting Bridge and choose reset preferences.