update.php just returns me to the homepage

Hi folks,

We are fairly new to Drupal, and have been working with a three week old installation with Ubercart. We don't recall whether we have ever run update.php since we can't recall having to upgrade any modules. We updated our Ubercart and found in the site's status report afterward that we had to run update.php to update the database schema.

When we ran this, we didn't know what to expect. We clicked the link, and immediately got taken to our site's home page. The status report still states that the schema is out of date. Repeated attempts did nothing.

We snooped around a bit and found other discussion about update.php that mentioned that when we invoke it, we ought to see some instructions about how to use it.

Tonight we did a fresh Drupal/Ubercart install on a different account/domain, and when we invoke update.php there, we indeed see the little "drop" guy with some instructions.

SO, now that we know something is wrong on the first site - can anyone advise as to how we might find out what is wrong?

Thanks,
Kim and Chuck