Can't Drop a Swatch into the Swatches Panel...

 I have an issue with AI and am wondering if any of you are too (or maybe it's me!)...it happens when I drag a new pattern into my swatches panel...I've gone over it a hundred times but now it won't work...I click over the whole pattern, drag it into the panel (and at this point, everything looks normal) but then I drop it and Nothing!

Any suggestions? thank you!