1) It's role and objectives aren't clearly defined
2) It's role and objectives aren't clearly understood across the business
3) It's value isn't visable
How do I deal with them:
1) Make sure QA is clear what it's supposed to deliver. It must have clear scope and goals. The term QA is standard, but is used to cover little bits of s/w testing, right up to ISO, CMMI frameworks. To succeed QA needs to know which part of the spectrum it's aiming for.
2) Make sure the rest of the business knows as much as possible about 1).