I have taken your suggestions under consideration. And at least one or two of the DS3 controlers are original sony controlers. So I took this a step farther. I have 2 sets of sony playstation move controlers and cameras. I used them to test to see what action I was getting from the usb ports on my slim ps3 and this is what I found out. Now they are all sony original camers and controlers and navigators. When I test both usb ports by plugging in any of the cameras or controlers all that will happen is that the power lights will come on to what ever I have connected to the ps3 so that leads me to believe that the usb ports are powering up anything I connect to them. But i get no pix from using my camera and i am not able to control my ps3 using the controlers while connected to the ps3 via power cord. There seems to be some type of a communication problem with the usb ports.
I noticed something weird lot of time ago, while i was doing something similar to you
I paired 4 DS3 to the PS3 by USB cable (one or a couple of them was not official), then i disconnected some/all and i pressed the reset button (at back of all the official PS3 controllers, the move and navigator controllers have them too)
Then i connected move/navigator/camera... and paired them too
At some point in between this experiments i noticed the firmware was not identifying them correctly (or/and the info displayed for them in screen was not correct)
To see his identifyers you need to press the "PS" button (and dont release it) in main XMB... this makes appear a black screen with info about the controllers at left-bottom corner
I was staying quiet in that screen when i was connecting/disconnecting/pairing all them, because you can see hos the info about them is updated at bottom (and it includes some kind of identifyer as far i remember)
Also, remember what i said about the reset button at back of all them... it was not doing anything handy for me though... but you know... incase of problems just press that button to reset them
I guess this should delete all pairing info they was storing from the PS3