can you add a text slide to iphoto slideshow?

You can't. The best you can do is have the title displayed but if that's used in iDVD it will fall outside the TV Safe area and not be seen when played on a TV set. You'll need a third party editor like Photoshop Elements, GraphicConverter, or Seashore to add text to the photo before using in an iPhoto slideshow.

Do you Twango?

Apple has been having problems with their servers the last few days. What has fixed it for me and others is to log into your .Mac account and reenter you account information and save. Some have reported it took them 5-6 tries before it took. Good luck.

Ooooops! I read that as adding text to a slide, not adding a slide of text. Is the latter what you meant? You can do that. There are several ways one of which is:

1 - in your text editor of choice create a custom, landscape page of 8" x 6" (for the 4:3 ratio used in iPhoto's slideshows).
2 - add your text to the document, format and color as desired.
3 - Do a Print to PDF but select the "Send PDF to iPhoto" option.
4 - you'll be asked to select an existing album or create a new one to add the jpg file of the document to.

This will create a fairly high resolution jpg of the document you can use in the slideshow, books, etc. Here are two rough examples of a letter sized document in both portrait and landscape orientation that I put in a book for demonstration. Once in iPhoto you can crop it further if necessary.