I began experiencing issues with my Droid Incredible shortly after installing update 2.3.4, including the "low disc space" error message that has been mentioned several times.
I did a reset of my phone, which cured the "low disc space" error, but then I realized I was unable to receive text messages, although I was able to send them.
I tried the fix that the above poster mentioned, and it worked.
Just to give a bit more detail, after checking the box, and going to the website, the download will complete in your notifications drop down status bar.
When it is done, click it to install, and it will say "Hotfix NV item reset it complete and you are able to receive messages now"
About 5 minutes later, all my texts came in.
Thanks for the help crazycatlady2352!