@Gammas Bearded Babies There is no need to turn the jars upside down after taking them out of the canner, it is actually better not to as it can allow the contents of the jar to get under the lid and prevent sealing. The only sealing fails that I have had is when I started out canning and was turning the jars upside down like I remembered Mom doing.
In My Opinion: The canning lids that you buy today seem to have a thinner layer of rubber seal than I remember the old lids having, so there is less material to conform around the lip of the jar and create the seal. I remember how mesmerized I was at the indent left in the seal when mom pried off that lid and I would run my finger along the indent all the way around the lid - I was about 6 years old at the time.