Question: Force Maple to defer evaluation of argument so it recognizes 0^0?

I've finally tracked down a problem I was having to a behavior in Maple I find, possibly, understandable, but need to figure out how to prevent.   Specifically, in expressions of the form x^y, where both x and y may sometimes be zero, the behavior I require is for Maple to evaluate y first so x^0=1 whatever the value of x is.   (Maple does evaulate 0^0=1 itself, I note.)

An example where this sort of thing comes up is in an expression like

sum(x^k,k=0..5)

This should evauate to 1 when x=0.  (Don't believe I would really want that?  How about  

sum( binomial(5,k)*a^k*b^(5-k) , k=0..5)

when b=0?   Would not the expected answer be a^5?   But that isn't what Maple 15 gives.   It gives zero.)

Something like this was buried in a much more complex expression where splitting out the terms with zero exponents would be very difficult, but if I can sort out these examples I can fix the problem I'm actually working on, I think. 

Thanks,

David