I have not experienced that, and have had good luck with BRY-97 fermentations so far, but one never knows what the dried package went through before you got it. When things are slow for the ales, a backup plan is always good. I have brewed several IPAs where I used BRY-97 as the backup plan (e.g., add it, rehydrated, to the primary after a couple of days of slow start), and it has always worked out well.