Just got my first glitch..
Regged 8 domains, paid via PayPal, the amount shows as deducted from PayPal, and I just received 8 failed registration emails for the domains I just paid for. These domains are not showing in my account.
The emails specify that there was a Billing Error. The emails arrived almost simultaneously as I hit the Pay button on PayPal.
If I can't get this resolved, no big deal, but be wary as apparently they have problems with their cart (as already reported by JasMate).
Sent the receipt number and info to tech..