Basically what it says in the title. If a guest chooses to register during the one-page checkout, when he clicks the final purchase button he gets redirected to an empty cart page instead of the success page ONLY when using Chrome. Everything works fine in Firefox and IE.
The purchase and the registration are still successful though, both the registration E-Mail and the purchase E-Mail are being sent.
Best Answer
I had the same cookie issue... I fixed it as follows:
go to "System > Configuration > Web > Session Cookie Management" and enter domainname.com in "Cookie Domain" & "Cookie path" /