EDIT: I think my problem's solved. See end.
I'm working on an Ubercart store using the documentation at Ubercart.org and Packt Publishing's Ubercart 2x book. According to that book and to Ubercart.org documentation, the form at Administer › Store administration › Configuration › Cart settings should have three tabs: Cart settings, Cart panes, and Cart block. However, on the new site I created, I see no tabs at all; there are the various settings expected for the Cart settings tab (General cart settings, Anonymous cart duration, Continue shopping element, and Cart breadcrumb), but there are no actual tabs, and thus no way to reach the settings for Cart panes and Cart block.

Any ideas on why this might be? I'm on Drupal 6.15 and Ubercart 6.x-2.2. I tried enabling all core and optional Ubercart modules, to no avail. The Theme is the default Garland. No funny cacheing- or optimization-related features are enabled. What could cause these tabs to be missing?
(I've asked the question at the Ubercart.org forums and the Drupal.org forums, and am still looking for an answer. Thanks to anyone who can help!)
EDIT: I'm going to sheepishly – if tentatively – retract my question. I've been unable to find any other folks with the same problem, suggesting that it's truly a bizarre quirk of my own setup, and not a Drupal or Ubercart problem per se, with a clean answer floating about out there. In the end, I tried "joggling" things: clearing cached data in admin/settings/performance (even though I have cache disabled); and, disabling and then re-enabling Ubercart modules. Somehow, those actions did the trick: I now get the missing tabs.
As happens with Drupal problems now and then, it's a welcome but unsatisfying resolution; it's the equivalent of smacking a TV to make the picture come in, without revealing anything about the source of the problem, how to prevent it happening again, and what to do if a future recurrence proves more stubborn. Sigh. In any case, things do look to be working again.
For anyone running across the same problem and this post in the future: You may be facing a "gremlins" issue and not a clear problem to be reasoned out. Try purging with any and all caches, disabling and re-enabling modules, and just general fiddling with things. Heck, try giving the monitor a few knocks; that just may do it. : /
I have heard and read stories such as this one before, and their common denominator is Drupal...
excellent tip - can highly recommend the module - installed and working perfectly in drupal 7
This book seems very interesting as I am currently starting a project to build a community site...
Thank you very much !
Thank you very much !