My slug suddenly stopped working. It just wouldn't boot up anymore. After trying to reinstall debian by flashing the installer firmware and booting it up, as soon as I attached a USB-Stick the slug would hang and stop responding to ssh,ping etc.
After some google research I stumbled upon a german site mentioning that a defect power supply would hang the slug as soon as a USB flash drive or hdd would be attached. So I tried attaching a self-powered usb-hub to it, with the usb flash drive connected to it and everything worked fine. Unplugging the flash drive and then the hub still didn't crash the slug. But the moment I attach the flash drive directly to the slug, the slug would crash.
I also noticed a humming sound, coming from the power supply, which I didn't recall hearing before. Therefore I am going to get me a new power supply during the next days and update this article should everything go back to normal again - however I highly suspect the power supply causing the hanging of the slug due to it being defect and the additional power, which is drawn by attaching an usb flash bdrive to the slug.
FYI the slug was running fine for about a year with debian installed on a flash drive and various usb devices attached to it via 2 hubs (including an external hdd,soundcard and IR blaster (USB-UIRT)).
Update: It indeed was the fault of the power supply. Checking the Voltage, it went from 5 V down to 3.4 V after starting the slug (without anything plugged in apart from the Ethernet cable. Replacing the power supply solved the problem and it is now working fine again.
defective power supply is also mentioned in paragraph 2 in the page relating to the power supply.