payment is frozen once the chargeback is initiated. input tracking number if it isn't already. stays on hold for up to a couple weeks. payment gets cleared back to seller. and then as long as like a month or two later, the payment gets frozen again (in the background paypal is 'disputing' the credit card company, which goes back and forth..) and up to a couple of weeks after that, the payment is finally really cleared to the seller.
it's annoying having the payment go on and off being on hold, but as long as you shipped to the correct address (not some random one the buyer requested in a note or message) and as long as you ship with delivery confirmation + with signature confirmation if $250+, you are guaranteed to end up with the money.
i always leave a balance in my paypal account, because chargebacks really happen often with high dollar electronics. i have one open chargeback at the moment, plus a bank inquiry/return (same thing as chargeback really), plus one payment that is on hold by paypal (they caught it before i shipped). all pretty normal, and paypal doesn't have any issues with me.