There is some confusion about the TMC error.
Technically, the eventual occurrence of the TMC notification can never be 'fixed' because it simply tells you that you've run out of RAM.
Since webOS (like Windows) is truly multitasking and won't close stuff behind your back without your express consent, there WILL ALWAYS be a notification that tells you to free up RAM if all your RAM is used by previously opened apps (like on Windows). It's not a bug, it's a feature.
We did use to have a bug - commonly called by the name of the TMC notification - in older phones that would tell you to close cards even if you only had one or two (or sometimes none at all) cards open. That HAS been fixed, although one can argue that the additional RAM in webOS2-capable devices is what fixed it, and not anything that webOS2 does or does different.
OP, if you're experiencing TMC errors on a Pre2 without having between 40 and 60 cards open, you should test around with not using any (possibly obscure) apps and patches you have installed and which you have observed to be running when the error occurs, because there are some buggy apps and patches that leak memory and will end up hogging all the RAM that you have. This is very likely what's happening to you.
There's very little else anybody can tell you because you have a relatively rare issue (as vouched for by all the people in this thread stating that TMC is gone). If everything else fails, there's always the nuclear option of doctoring your phone, but it's highly likely that the issue is caused by an app or patch you're using, with homebrew being more likely to cause issues because of its lack of testing when compared to HP-approved catalog apps.
The scientific method.
Originally Posted by BradleyCulbertson
Next time you observe a TMC notification, make a note of the apps you have open at the time. One of them is bound to be the culprit although recently closed apps could also be at fault. After two or three TMC occurrences, you should be able to see some overlap.
Rule out stock apps and semi-rule out really, really, REALLY commonly used apps that everybody else who doesn't have problems is also using every day (like Angry Birds, Pandora or Govnah).
You should now have a rather small set of suspicious apps. Write them up. Now don't use the first app on the list. If it still occurs, start using that app and stop using the second one instead. And so on, until you don't see the TMC error at all anymore. You have found the offending app - and should tell everyone including the Dev about it!
(we should really have a thread naming known memory-leaking apps somewhere, as a directory for people who are getting TMCs when they shouldn't be getting any to look in as a first step)