1.As someone who uses QR codes in marketing materials, I had to try this out for myself and see if I could figure out what was happening.

Here's what I found:

Google Goggles seems to be simply overreaching in an attempt to link users directly with what they're searching for. Specifically, although the URL embedded in the QR Code _should_ link to marketplace search results, Goggles assumes you want the actual app you're searching for, and consequently takes you to the first app in the search results.

BeeTag poses a more interesting issue. The link stored in the Sprint QR code is this: market://search?q=pub:"EA Mobile". However, BeeTag passes the link to the Market app in all lower case, "ea mobile". Publisher searches in the Market are, apparently, case sensitive, so no results are returned because the actual name of the publisher is EA Mobile. If BeeTag treated all URLs in the same way, services like Bitly (which are immensely popular among QR Code generators) would also not work with the app. Fortunately, it seems to only behave this way with Market links.

In my own testing, two other popular QR Code readers, ScanLife and Barcode Scanner by ZXing, were on par with QuickMark and worked as expected.

Of course, none of this means you shouldn't test your QR codes as much as possible before using them--that point is well made. It just means that the problem, in this case, was not with the QR Code itself but with either bugs (BeeTag) or "features" (Google Goggles) of the apps themselves.

2.Thanks for all the work, Dagan. I actually never suspected the problem was with the code but rather assumed it was, as your research points out, with how the different tag scanners interpreted it. But that's the point, isn't it? People who create the codes can't assume every reader will handle the tag the same way and, based on testing, should come up with a destination that DOES work consistently regardless of how the scanner is configured.