I had the same thing happen and I use it in the oven with no problems...

I use mine in the oven with no problems. I have a stone crock and a glass lid.

You might want to call the manufacturer to check. I hate you to have it go crrrrrack and lose your food that's cooking. To say the least about the mess to clean up!

I often use my crock as a large mixing bowl!

I agree with this. I would give it a try in the oven before trying to actually prepare something in it. See if it will hold up to the normal oven temp.
Here is a link for you to check out that talks about this subject.

http://chowhound.chow.com/topics/343987

Interesting!

At Thanksgiving my sister always baked her broccoli casserole in the crock pot insert in the oven and then put it in the metal part to keep it hot. Never any problems.

I use my old crockery liner in the oven - like the size for large piece of elk roast, or fpr casserloe to serve large group of family/friends.

If you did want to use it for a planter, all you have to do is put some broken crockery(plant safe),broken terra cotta pot, or stones in the bottom for drainage. Works like a charm.

I can testify that you should not put it on a burner. The oven
on a low heat, I'd say yes. I have a metal slow cooker now
and love it. From the burner to brown and into the oven or
on the hot plate that it cooks on. Really nice and convenient.

Not on the burner but I use an old liner for my bean pot quite often. it works very well.