Funky screens in between screens?

Hi there,
My apologies to you all, I am very unknowledgeable about computers.
I have a mac OSX 10.4.8 that is a shared computer.

I recently have had a strange thing happening and cannot figure out why...

When I check my email from Yahoo or go onto my Myspace page I am finding that occasionally I have a screen (page) that shows up between loading the pages.
It looks like the page that will load as far as the information, but without graphics. Very bare bones in appearance, only blue text, simple white ground.
Then it quickly (within a second or two) disappears and loads the actual page.
This has never happened until recently.

Any thoughts why this is happening all of a sudden.

Thanks!

This looks like a popup or popunder window trying to load. Your browser may be set to block them but is only partially successful. Download and install an adblocker for either Firefox or Safari, and in the Preferences of either of those make sure that Block Popup Windows is enabled.