I seem to have a pop up blocker that doesn't like to allow me to open boxscores.  I do not recall installing one.  How do I check this out to try to remove it or to allow pop ups on WIS??

Depends on the browser.

Chrome - go to options (the wrench in the top right), then to "Under the Hood" on the left pane.  Right next to "Privacy" at the top, there's a "Content Settings" button.  Click that and then you can go to the "Pop Ups" section where you can either allow pop-ups on all pages or none and then click "Manage Exceptions" to add in whatifsports.com.

IE7+ - go to Tools, then the Pop Up Blocker option.  If your pop up blocker is turned on, click on "Pop Up Blocker Settings" to handle exceptions.

Firefox - Go to Tools >> Options >> Content.  Click on the top option "Blcok pop-up windows" and then handle the exceptions on the button to the right.

If it's an add-on like the Yahoo toolbar or something, then you can just uninstall it.