I hate Paypal but I was feeling lazy and went through a phase of ordering a few things using it.
There were some smaller items where the retailer was paid and has sent the items.
One item was £400+. Paypal have apparently made my payment an e-cheque. I didn't do anything different from the items that got paid immediately. The money has been taken from my account, but apparently Paypal won't give it to the retailer for some time.
It is not apparent why Paypal have chosen to make my payment an e-cheque or why they hang on to my cash for such an obscene amount of time. It's not possible to get hold of them to ask - their FAQ system doesn't provide any worthwhile information.