To head off any confusion, I thought I would post this announcement:
We just discovered an issue with the 2.5.5 build available directly from sandvox.com that caused a hiccup if you tried to buy and register a new license to Sandvox from within Sandvox. So we've corrected that and posted 2.5.6 to sandvox.com. It is a very minor update, but you'll also see it come through Check for Updates so I thought I should mention it here. If you are a Mac App Store customer, this is not an issue.
We'll resume with normal feature updates and bug fixes, and sync up the version number with the Mac App Store again, for 2.5.7 and beyond.