Shipping amps upside down?

I recently recieved a used amp that was shipped upside down. The sender will remain nameless as he is a decent guy and went out of his way to get it to me quickly. However the fact remains that the address label/postage was on the bottom of the box (which was the top for the entire trip, even with all the *up* arrows pointing the wrong way) The trip was probably close to 3000 miles, but was shipped essentially 2 day air. I cannot hear any parts rolling around and it performs like it is supposed to as far as I can tell (but volumes are low right now as the wife and kids are sleeping) I have heard horror stories about electronics being shipped upside down. But in my case should I worry or not? The amp is SS but it weighs in at 50 lbs. Could there have been damage that will show up in the near or far future? If I sell this amp in 2,5,10 years should I still be concerned about it? Sending it back to the factory for a check-up probably involves another 6000 miles of travel. Would more harm than good be done by that?

It just bothers me to have to worry about something like this.
I wouldn't worry about it.
For peace of mind you might want to talk with the manufacturer's packaging engineer or designer to get their take on potential problems. I would expect that if the unit was shipped in factory packaging and the packaging and amp have passed standard shipping vibration tests that you are probably ok.
There should be very little to worry about except for different amounts of packing on top vs bottom possibly resulting in physical damage, but you would see that, and increased potential for capacitor oil to leak. But most any tech should be able to check that for you unless opening the case invalidates whatever warranty there is. There may be other problems but I am not aware of them.
Do you really think UPS or Fed Ex or USPS pays any attention to the direction the arrows are pointing on a shipping box? In my experience, all these services are HARD on packages. I would have NO confidence that labelling and other instructions are followed during shipment; for all you know, your box was actually shipped UPRIGHT because UPS or whoever ignored the arrows pointing the wrong way. Sorry to be so cynical, but I have shipped and received many packages delivered upside down, sideways and everywhichway but loose.
I wouldn't worry about it.

you are right on, on this one!
The problem is that you don't know how hard the impacts were on the box at all. The heaviest thing in the amp are the transformer(s) and they could tear loose or bend the sheetmetal Then the thing would not play. I would not worry about it if it plays and isn't rattling or bent.
(I had a big ol' amp that fell to the floor from being carried and the frame WAS bent when the transformer tried to continue on it's path when the rest of the thing stopped at the floor. it played ok but the bend in the chassis was VERY evident)
if it plays don't worry about it - most high end stuff is built like a tank, especially amps and speaks.
Sad to say, but I too think Sc53 is right on. Personally I wouldn't worry about it unless the amp was malfunctioning. Good Luck. Craig.
I get a laugh (cry) everytime I visit my local FedEx Truck Depot to drop off a package. In the lobby there is a photo of one of their large sorting centers, probably the national hub in Memphis. I guess it's there as a way to show off their operation. Near the center of the photo there is a really large JVC Television box (probably a 32 or 35 inch set). It looks definitely like an OEM box (ie, its not Aunt Margaret sending her Christmas gifts.) Well the box is upside down. I wonder who at FedEx chose that picture; they must have been asleep.
I wouldn't be too quick to dismiss the potential of an upside down effect. I recall a mid-70's article in one of the Russian aerospace journals that referred to "capacitor confusion" resulting from quantum acceleration phonomena. Something about discontinuous gravitational fields. This may be one of the factors involved with "break-in". Anybody doing any controlled listening?