Tracking Products through the sales process

Tracking Products through the sales process

OK, I am baffled by this one. Need help.

In a Lead, I can associate products with the lead.

I can convert the lead to a potential and have the products associated with the lead carry over.

I can also just create a potential and associate products with it.

When I was to produce a quote for the potential, why can I not (or how do I) carry the products associated with the potential into the quote?