If the money hasnt cleared, the buyer hasnt made good on his payment yet and it can be reversed so the seller could end up with no payment and no item if he has sent it. Dont send until its cleared. In the case of echeques, Paypal / eBay are quite clear that you are not covered for seller protection until it shows as being cleared.
I had a dispute with one buyer and PayPal actually was able to take the money back from my bank account without my consent when the dispute was opened by the buyer. He had my items and PayPal had my money after the money had cleared and been put into my checking account. I was very PI$$ED OFF, but when you create an eBay account and PayPal account, you had better read the fine print about what they can do to you and your linked bank account when a dispute is filed against you.
It was all caused because of the rough treatment the box received by the US Postal Service, and I ended up having to pay. Seller beware! Pack everything like it is going to be handled by a gorilla, instead of a person.
I asked the buyer to just return everything and I would refund his purchase price, but he would not agree to returning the items, which made me very suspicious, so I will no longer do any business with him.
Edit: If it had been for less money, I would have fought the dispute, but it was $600 that I needed at the time that they had removed from my bank account. The seller did not want to pay for insurance, something I won't let happen again.