Make sure the Verdana italic font is enabled on your computer.
This happened to me out of the blue and after many hair pulling days, I figured out that if you set one of your layers to "not print" (by un-checking the print box in layer options) all of the text and icons disappear off every layer below that non-printing layer. So find the non-printing layer, click on it, go to the drop down menu at the top right of the layers palette, choose Options for layer, and check the "print" box. All of your layers should now look normal.
I also read something about making sure the Verdana Italic font was active in your system fonts which mine was so that suggestion didn't help me. Good luck.