xeloda dose question

I have been on gemzar and xeloda with herceptin for 7 months now. It has worked really well for my lung mets. However, I am having trouble with the xeloda now. Initially, the onc started me on 3000 mg but quickly reduced me to 2500 and then to 2000 mg.

But now I am having abdominal pain, fever and diarrhea with the last couple of cycles. I know the obvious answer is to reduce the dose of xeloda yet again but I am really afraid to. I have been told that there is a very sensitive line with xeloda and dose beyond which it is not effective.

For those of you on xeloda, what doses are you on and when you were reduced how did you do?

Thanks