My US citizen Son and I are about to file both the I-485 & I-130 forms together. I am have now overstayed the allotted 6 month period allowed for Canadians. I have been advised to file the I-601 along with the rest of the forms. Others tell me not to.. I'm confused! If overstay is forgiven for immediate relatives (or is it?), then why would I need to file that form?