Although you can consider it a "lab" phone, we have taken steps to create a typical pattern of use--installed/uninstalled multiple applications, tested phone calls (while running white noise), ran/used facebook, ran instant messenger, configured and used e-mail, installed lots of multimedia, and in addition we have probably put stresses on it that exceed normal use such as installing/deleting/reinstalling/debugging our own suite of applications numerous times. I wish I could say we found the reason for the reboots but we have not experienced it yet. It would be helpful if everyone experiencing problems would provide a list of applications they are running so that we can better simulate your environment. We did use the list that landeisj provided and installed those applications.
With that said, we do have some news to report: We decided to investigate our codebase, mainly the sound looping algorithm, for possible improvements. I'm happy to report that we have successfully reduced the memory footprint of white noise by half. It also has made the application a lot more snappy. I have sent landeisj a special build so that he can test on his phone that is having problems. I feel pretty confident that reducing the amount of memory used by an application can only help, especially if there are multiple applications running.
We will be submitting v2.1 that includes lower memory usage (and some other minor fixes) but want to run it through it's paces first. Again, If everyone can provide an application list for what typically is running on your phone we will add it to our tests.