Here the same problem. I don’t use paypal, so that is not the problem. At the past 3 weeks my store is online i’ve received already 3 times an payment email from my iDeal provider(mollie) but NO order-email from RCP. I must return an little amount to the customer (via mollie refund) and ask them for their order by email again.
This is not happen everytime, the ratio is about 1 on 10 that will not send order details to my email. Also no order-details in the Admin-area!
Very strange problem, because when the user has paid the order via an payment-provider the Cart has done all the work good, just the ordering-email is failling sometimes!!