Repair Table After Server Upgrade
Since you have PHPMyAdmin, you should be able to fix this with some point and clicking. 


Navigate to the node_counter in your Drupal database
Go to the 'Operations' tab
Hit check tables
If something isn't right it should give you the option to repair


If the option to repair doesn't come up and it doesn't appear in the Operations tab (some of these move around version to version of PHPMyAdmin), you can run the command

REPAIR TABLE node_counter;


from the SQL tab.

Good luck!