Save Optimized won't save as .gif

[monae]

Hello,

Every now and then I have a problem with slices saving as .gif file. I create a psd file in PhotoShop then edit in Adobe ImageReady. I create the slices from guides, set my output setting, then when I do File, Save Optimized Settings and try and change the Save as type, it will not let me save as .gif. Only .html or .jpg. How do I make it save as .gif and what am I doing to make it default to this?

Thanks in advance,
MonaE