I found a thread on Google code about the Messaging app being killed on low ram scenarios.
So, if we spend 20 second of our life puting a star (top-left corner) on this thread, we can use our 'force' to make Google correct this code mistake!
Link: Issue 3836 - android - Text message never received - Android - An Open Handset Alliance Project - Google Project Hosting
For those who use stock roms without "lock in memory Messaging" option, please feel free to put a star on it!
For those who use other roms with/without "lock in memory Messaging" option, please help us to get rid of this problem!
Any question, please reply to this topic and I'll answer it!