I recently added 2 more 48-port gigbit blades in my Cisco 4510R switch chassis, which is now maxed.. the blade in slot 8 is recognized no problem, but the blade in slot 9 is not....
to rule out the blade being the issue, i removed the blade from slot 8 where it was working, and put in slot 9, and still did not work...
The sup V-10GE has 2 x 10Gbp uplinks on the supervisor. It also increases the available switching fabric which is why you can run all linecards in slot 10.
Do a "sh pow avai"
It will show you how much you are using and how much left to use