Hi Roz! Sorry I didn't see this before now. I am about as certain as it's possible to be that the echo command could not have caused your problem. A few thoughts on what could have:

1. If you have used iplayer-dl URL at all. As mentioned in previous posts this is a bad idea because it could fill up one of your partitions very quickly. This could have a number of strange effects, perhaps yours included.

2. If you have been using the "reboot" command or something similar to restart your device instead of powering down fully. See this post for details.

3. The specific command listed here should not cause any major problems whether issued as user or root, but if you have got into a habit of using "sudo gainroot" more often that the instructions tell you (as you suggested earlier) this makes it much more likely that you'll accidentally cause major problems.

4. Unless someone else reports the same experience as you I would suggest it's extremely unlikely that this process would have had the effect you describe. Have you installed any other potentially unstable software (i.e. enabled extras-devel or extras-testing)?

If I were you I would check out the thread linked to above and see how you go. I'm sorry that I can't think of any other explanations.

Cheers,
Jan