Some buttons, when inactive, can still lead users into false assumptions. For example, the "Show 10 more results" button (see attached "ez_support_issue_5747_screenshot_1.png" screenshot) can be inactive, but the button text will still be green, which is a visual clue that it is OK to click the button.

A possible way to go around this is to change the color to red (or any similar color that fits in with the page's color scheme). Or to make the button invisible altogether.