"Low on space" Message Even Thought There's Plenty Of Space Left

Question

On Sunday I started getting the message
     "Low on space
     Phone Storage space is getting low."
on the status bar.
When I tap it, I'm taken to the "Manage Applications" screen, so it's clear that the message refers to the "Phone Memory," where apps are stored.
But when I go to Settings > SD card & phone storage here's what I see:
SD Card Total Space: 14.83GB
SD Card Available Space: 6.15GB
Internal Phone Storage Total Space: 6.60GB
Internal Phone Storage Available Space: 6.51GB
Phone Memory Total Space: 748MB
Phone Memory Available Space: 332MB
I've googled looking for solutions and it's obvious that this is a fairly common problem - especially on HTC phones. But the only possible solutions I've found are:
Too many apps are installed & space really is running low
A "bad" app was recently installed causing this error
Clear the cache for HTC Mail and HTC Message apps
Perform a Factory Reset
We can rule this out since there is more than 44% of the Phone Memory available.
I didn't install any apps immediately before getting the message, but to be sure I uninstalled the 10 most recently added apps. No luck.
I've gone to Settings > Applications > Manage Applications, but the cache for these apps is already zero.
This isn't fixing the problem, it's just a way to eliminate whatever condition has caused the symptom. But without an explanation of the actual problem I see no reason to think the problem won't come back in another two months.
And finally, yes, I've rebooted & pulled the battery.
I've spent more than two months tweaking my Incredible getting it set up the way I want so I really don't want to wipe all of that out with a Factory Reset.
Any other ideas?

Answer 1

i had the same problem. did a lot of research..my phone became unusuable. do you use the htc mail? if so that is your problem. there is a bug with it that it keeps eating your memory until you cannot use your phone. i had to do a hard reset. back to factory condition..not happy! but then went to the marketplace and got k-9 mail. that is now my default mail program. i have not had any issues since then. this is what i kept reading over and over for complaints on this phone. it is a major glitch and the only way, as of the time it happened to me, to fix it..