I want the pi to be nice, it just isn't responsive enough to be usable. I tried the pi app store on a new 512mb pi and the recommended raspbian image. The pi store is broken, clicking on anything takes you to the library tab, a white square, and after a second takes you back to the original tab. Of the 8 or so apps you can click, none of them work. Yeah I tried more than 1 pi so its not that I got a broken pi. Not sure what to think about the pi, just that its only useful as a commandline embedded computer.
The biggest problem I have found with the RaspberryPi is that they tend to lock up under load. I have two Model B's, one the latest revision and one the first revision and neither will stay up longer than about 1 to 2 days, especially when doing heavy reads from the SD card...
Sounds like a power issue. I am not sure how you supply power to your RPi, but I had this problem where I was drawing power from a the USB hub. My goal was to only have one power cable. So I had the hub and the RPi connected twice. First, a USB host port on the RPi <=> upstream port on the hub. Second, a random port on the hub <=> power on the RPi. Then, the power cable goes into the hub to supply juice to the whole setup. The wall wart for the hub is rated at 2.5 amps, so plenty of power there.
There are two things to be concerned about here. First, the RPi can draw up to 700 mA, but a normal hub will only supply 500 mA. Second, a USB hub might not be as good of a power source as a dedicated power block. The first concern is addressed for me by the fact that I'm not running anything CPU intensive and not using the HDMI port (the setup is headless). The second concern did bite me when I plugged in a what I suspect was a faulty or at least a power hungry USB WiFi dongle. The RPi would lock up after about 1-2 days and I'd have to power cycle it to get it back. After I switched to a different WiFi adapter things got a lot better.