iPhone 4 Memory Issues??

I have recently been experiencing what I believe to be memory issue with my iPhone 4….I am thinking they correlate to my updating to 4.0.2, but I can’ be certain. So here is the problem….I will be functioning within a App and it will “Express Exit”, the App will show on the Multitasking list and when I launch it, it starts where it left off…but immediately closes again. Once it starts happening with one, it happens with all…until I restart the phone. Once I restart the phone, I can operate normally for a little while…but depending my usage it may not last long(usually have to restart between 4 to 6 six times a day). I am very anal about leaving a bunch of stuff running in Multitasking, if I am not going to get right back in the App then I completely close it. I have downloaded the FreeMemory App and checked the amount of available memory when this behavior occurs and it is indeed very low(somewhere in the 40s). Also, as a test I have restarted the phone and immediately launched only the Free Memory app and my available memory constantly trickles down to the 40s and then the Free Memory App closes. Now, I know the Free Memory app is going to take some resources…but I don’t think it would explain that drastic of a drop. Is anyone else having similar issues? Tonight I plan to reset my phone back to factory settings and set everything up again…hoping I just have a glitch. I will post the results.