Sob!Sob! Sob! Years ago Tupperware made ideal cereal containers which had flat tops on them which enabled them to be stacked in a cabinet. Some of mine are no longer useful, so I wrote the company and talked to a rep, but they no longer make them, even with multiple requests from other customers. Sometimes when things work so well, why must the manufacturers change them? That old saying "if it ain't broke, don't fix it" must not appeal to younger folks.

I just left lid on the container until it cooled. I did not put any weight on it.

Almost anything Tupperware can be replaced......just call the company or representative and tell her you need.....

I know that here in Australia if you contact Tupperware they will replace your warped lids free of charge. If you contact Tupperware I am sure they will help you.

A great many of their things are now "obsolete". If it needs replacing, you will get credit for the item. As in my sugar bowl and seal, which cost $.79 in 1951. That's when Tupperware started. They still give you credit if it is cracked, broken, chipped or peeling.

But a warped seal (yes, they are called seals, not lids) may or may not be replaceable. Depends on your distributorship.

Sometimes the old stuff comes back for special promotions or seasonal. Like the fix 'n' mix bowl. It's been for sale every once in a while. While it is for sale is the time to get it or its seal replaced.

Tupperware will replace it for free -- just go to their site.

Years ago, if the elastic broke in the Shape-O ball, you would get a new elastic and you could replace it yourself. Now if you turn in a Shape-O ball, you get a whole new ball. And you used to be able to buy just the shapes that were lost. Now you have to buy a whole new set of 10 shapes.

I took someone's Shape-O ball and put a very strong rubber band into it. Works well.

I also had a Tupperware container that had lost its seal. The company no longer made that particular one. I found a replacement for it on Ebay and later found a second one at my local thrift store. The ladies said they sell a lot of seals for Tupperware and are always glad to get them in. I bought the one I found there to have a back-up since I have two of the containers.

I used to be a Tupperware agent. I still have a few and I have the cereal containers. I wash mine often but never in the dishwasher no matter what. Whatever piece you have seal or container on the bottom should be a number. The pieces may be free but yes you have to pay for shipping. I just had a seal replaced the other day. I also do not put them in the microwave. I have gotten to where I only use paper plates (not foam) or corning ware or regular cereal bowls or cups in the microwave. Nothing plastic or foam. Those seam in bags of frozen veggies get emptied and put into a regular cooking micro wave safe cookware.

If this is one of your favorite pieces, and they don't make it anymore, I suggest you put the lid on it, and set it out in the sun. Sometimes, the heat of the sun "warps it back".

Good luck and let us know if it works.