And the starter fermented OK?
I've definitely seen the older yeasts go really slow. Once I got an infection because of the lag time. A vigorous starter is essential.
48 hours would be worrying me. I might get some dry yeast in there if you don't see activity really soon. In the future, you'll have much better results with really fresh yeast. The White Labs Wit yeast I started Wednesday was fermenting within hours.
Oh don't give me none more of that Old Janx Spirit
No, don't you give me none more of that Old Janx Spirit
For my head will fly, my tongue will lie, my eyes will fry and I may die
Won't you pour me one more of that sinful Old Janx Spirit