I purchased Carbonite and downloaded 2.511.  When I try to activate on add ons it says it is out of date.  I check load out of date and it does not show up when logged in.  Can anybody help with this problem????  Thank You.

Sound like you have Vista and your addon folder was moved, so when you unzipped 2.511, you put it in the old location and it is not being loaded.

If you have Vista, then the 3.0.2 patch moved your AddOns folder if you clicked OK when asked.
 
Look at the shortcut (right click and select properties) you use to launch Warcraft to get the path to where it is installed.
 
Possible locations for the AddOns folder:

Windows XP: "C:\Program Files\World of Warcraft\Interface\AddOns"
Windows Vista: "C:\Users\Public\Games\World of Warcraft\Interface\AddOns"

Unzip the the Carbonite zip file to the AddOns folder.
 
 
Debugging steps:
 
Reboot the computer.
 
Look at the shortcut (right click and select properties) you use to launch Warcraft to get the path to where it is installed.
So if the shortcut says "ABC\World of Warcraft\Launcher.exe", then your addon path is
"ABC\World of Warcraft\Interface\AddOns".
 
In the file paths shown below, you need to replace ABC with the actual location!
 
If you have an old version of Carbonite, then delete any existing Carbonite folders before unzipping it.
 
If you have an old version of Carbonite, Run WoW and check addons list. Carbonite should not be in the list. Exit WoW. If it was in the list, then it is being found in some other location. You need to delete it from every location, so you can have a clean install.
 
Unzip the downloaded Carbonite zip file to "ABC\World of Warcraft\Interface\AddOns".
You would now have a "ABC\World of Warcraft\Interface\AddOns\Carbonite" folder.
Look in the Carbonite folder. Do you see Carbonite.lua, Carbonite.toc and Carbonite.xml files?
 
They would be at
"ABC\World of Warcraft\Interface\AddOns\Carbonite\Carbonite.lua"
"ABC\World of Warcraft\Interface\AddOns\Carbonite\Carbonite.toc"
"ABC\World of Warcraft\Interface\AddOns\Carbonite\Carbonite.xml"
 
If you don't then you probably made a Carbonite folder and unzipped into that, which will not work.
 
You unzip the files to "ABC\World of Warcraft\Interface\AddOns". The Carbonite folder will be made when you unzip the zip files.
 
Run WoW and check the addons list by clicking "Addons" on the character select screen. Carbonite should be shown. Log in with the registered character. Check the version number in the Carbonite minimap button tooltip.

Does the Carbonite minimap button tooltip actually say 2.52? If yes and it say expired, that means your computer clock is wrong. Set it to the correct year, month and day.

If it does not say 2.52, then you are probably unzipping it to the wrong folder.

Look at the zip file contents before you unzip it. You should see a Carbonite.xml in the Carbonite folder inside the zip file. Delete the Interface\AddOns\Carbonite folder before you unzip the zip file to Interface\AddOns.

Zip file structure:

├──Carbonite
│  ├──Gfx
│  │  ├──Buttons
│  │  ├──Map
│  │  └──Skin
│  └──Snd
├──CarboniteNodes
└──CarboniteTransfer

Carbonite folder contents:

Bindings                                                                .xml
Carbonite                                                               .lua
Carbonite                                                               .toc
Carbonite                                                               .xml
CarboniteLicenseAgreement                                               .txt
CarboniteReadMe                                                         .txt
Localization                                                            .lua