Was the pollen fresh?
This sounds like you had a batch of pollen that is no longer viable or the particular bloom had sterile pollen. If either of these are the case, you would need new pollen (if you were using frozen) or another bloom. Some plants will take a while to give you a bloom with nice fluffy orange colored pollen.
It could also be a number of other things - heat for example - but I am sure others will chime in. If it was too hot, you could, if possible, move the plants into an area that stays shaded and will keep the temp down, or do your pollinating early in the morning.
