Any Firmware upgrade issues?

I hope none of you had any of the issues such as firmware not taking and locking up your Sansa. I tried installing the firmware today, and thought I had lost my Sansa for good. I called Sansa's customer support twice. The new firmware did load, but the Sansa could not use it. I tried using a file they provided to go back to the original version, but the software did not work on my machine....I tried another machine in the house and guess what...it worked just fine. My machine has multiple usb devices installed on it, my other machine does not. Please post if you have similar or other problems. Together, I'm sure we can figure this out.