If you have any other addons that do anything with the minimap buttons, either disable them or go through their options and see if they are hiding the buttons. You can check to see if another addon is interfering with Carbonite by disabling
all addons except Carbonite. If the problem stops, it's because another addon is doing something with your minimap buttons.
If that doesn't work, try this:
Open your
"Path to your WoW folder\WTF\Account\ACCOUNT NAME\SavedVariables\" folder and rename or delete the "
Carbonite.lua" and "
Carbonite.lua.bak" files.
BE AWARE that doing this
will completely reset your installation of Carbonite, and it
will look and act as if you have just installed it for the first time on
ALL of your characters. This happens because those files contain Carbonites set up information for all of your characters.
If THAT doesn't work, the only thing I can think of is that your Carbonite installation has somehow been corrupted. The only way to correct that is to do a complete reinstall of Carbonite.
Start by deleting the previously mentioned files in your WTF folder. Then open your
"Path to your WoW folder\Interface\AddOns\ folder and delete the four Carbonite folders there. These will be: Carbonite, CarboniteItems, CarboniteNodes, and CarboniteTransfer. Next, go to the download site of your choice (
Carbonite at WoWI or
Carbonite at Curse) and download and reinstall Carbonite. Start WoW and set Carbonite up the way you like it.