slow fermentation start

i used a White Labs yeast for a hefe and the pamphlet said optimum fermentation temp 65-69 degrees but the vial says 70-75 degrees. which temp should i go by?

I'd follow what this says for your yeast strain: http://www.whitelabs.com/beer/homebrew/listings

Some brews need specific temps to be in "style" or create specific esters and tastes. I would go with the directions for the kit as long as the max temp doesnt exceed the vial allowable max temp. Hefe's are one of those types that develop certain flavors from special yeasts and from certain temps. If you want a great hefe and not just a good hefe follow the kit directions first, especially if it is a kit from one of the larger suppliers. They have been doing it for a while and dont ususally give out bad info..
Just my .02...

Wheelchair Bob