I don't know why you're getting such a high (negative/low) number for RA, but try adding some Baking Soda to your mash water (not sparge water, and on the spreadsheet only) and see what that does to the rest of your numbers. Also, are you using acidulated malt? Tweak that in the spreadsheet as well and see if you can get a profile more tolerable.
Edit: this thread is jumpin'. My response is already obsolete. As long as mabrungard and AJ are helping you, ignore me. I've had this problem as well and adding a bit of baking soda to my mash corrected it, but these guys will give you way better info then me.
For AJ/Mabrungard: Is there a negative impact of having too low of an RA (presuming your ph numbers are correct)?