Disappearing Products in 1.4.8b

I recently discovered some strange behavior that I don't know what to make of.

A product that looks completely normal in the back end, and is (of course) enabled, does not show in the front end. I've used search to try to find it, and looked in the categories to which it's assigned, but nothing.

I'm now going through my entire product list and have found at least 10 more products that have simply disappeared this way in the front end. Nothing I do to the product from the admin will make it reappear, including copying it. For all affected products, I've had to delete and recreate them.

I've been trying to figure out what they have in common, and the answer is, nothing, expect that they were likely created by copying them from another, or were themselves the original copy. I created a whole lot of my catalog this way.

Anybody have an explanation for this? I'm really, really hoping this was a one-time thing and products won't continue to disappear this way.

Don't honestly know whether this is a bug or something else is going on - forgive me if it's not.

dıd you delete your browser cache?

Are you usıng a custom theme?

No, and yes.

Change the theme back to the default theme and have a look to see if it's a theme problem.
I suspect it could be data problem. Did you by any chance migrate the data from another database.

Check your data by
Try simply saving the product again. Not sure if you're already done this
Then try and change something in the product and save eg just change a character in the title
Then go and have a look at every field and make sure they have something in it
The copying sounds like it's copying the same problem to the new product_id.

What I'm getting is, there might be a field that needs something in it but is currently NULL or blank.

The faster way to do this is to have a look at your data in phpmyadmin (if you have phpmyadmin) and compare the rows for a good product with the misbehaving ones.

Thanks for the help! I'll do this with the next one I find.