Bit late, but posting this anyway in case it's helpful...
this site is very good for paypal queries
Look under 'Pending Payments for Buyers' and 'Pending Payments for Sellers'
I recently bought something on ebay and instead of my Paypal payment going through instantly as usual, the buyer was informed that my payment was uncleared and 'pending' and would take 7-10 days. When I looked at my Paypal web account page the payments were there and said 'uncleared'. I checked my bank account and the money had come out, but had apparently disappeared into thin air (or to Paypal's account .
I looked at Paypal FAQ 'Why does it take seven to nine working days to add funds to my account or to complete an Instant Bank Transfer payment or eCheque?' and the answer is basically "because it does".
I emailed them to ask why it never used to take that long and have so far not received a reply.
I did some googling and found the site above, apparently one of the common reasons is that if the credit/debit card that you have registered with Paypal has expired, they will request the money from your bank account instead, which does take 7-10 days. If they take it straight from your card it is more or less instant - like in a shop I guess. My card did expire a couple of months back so I went in and updated my details and am hopeful that this will fix the problem.
Annoying that this info isn't in Paypal's FAQ - could it be that they are enjoying a bit of extra interest on the money that is taking so long to clear?