I know you think pulling the battery is like putting a band-aid over the problem without addressing the issue, but sometimes it's a necessary thing to do.
You should delete any unnecessary emails, pin messages, texts and stuff that you don't need on your berry. This used to happen to me. A battery pull doesnt fix it. That should fix the problem.
This just started happening. Sometimes after 2 days sometimes after 2 lines. And I'm nowhere near savvy enough to even know that option exists let alone enable it (auto delete option)
Posted from my CrackBerry at wapforums.crackberry.com
go into Messages, then BB menu, then options, general options, scroll to bottom and look for Keep messages it will say how long it keeps messages for before it deletes them.
**EDIT**
I will keep looking, i think that is the only place i have seen it.
You should delete any unnecessary emails, pin messages, texts and stuff that you don't need on your berry. This used to happen to me. A battery pull doesnt fix it. That should fix the problem.
That's only an issue if you're running low on free file memory. Her memory looks good to me...