Here's some wisdom i gleaned from my computer today:
This afternoon when my flash drives weren't reading, I decided my MacBook needed to rest--to be shut down. But, it was taking a really longgg time to shut down. So, in the end I forced it to quit by pushing the on/off button. Afterwards, I let it rest in blackness for a few minutes. When I restarted it--VOILA--everything was working fine; my flash drives were reading.
Nicole's points of wisdom:
When you aren't "reading", shut yourself down. Push the off button and rest in the darkness for a few. When you eventually restart, you will be fine.