I was writing a review, and wanted to check on something that was in another post, on another page, for the same song. When I clicked off of the page that I was writing the review on, onto the other page, the stuff I had writen already was erased.
 IMHO I think it would be helpful if while writing a review you could click to back to a previous post on another page, and not lose what you had already written. I usually post reviews without trying to be influenced by other reviews, but I do read them, and sometimes it's good to respond to a previous review about a song.

Every now and then I forget that this happens, and do the same thing!
However, when I remember    -  I open up a new tab (or page depending on what browser I'm using).  That does the trick. 

that happens to me sometimes as well hehe...

And I think it would be also helpful to change pages while listening to the song...

Me too, I usually run several tabs of BandAMP, what I also do, before pressing the post button to any comment, is select the text and copy to clipboard (with CTRL+C). that way if anything goes wrong, like it sometimes did in the past, the text will be saved, I can simply paste it back with CTRL-V. This is what I do when looking at other pages of the same thread too sometimes, if I don't have another tab open. It's a very reliable way of solving the problem

I'll start doing that.

play the song on The Bandamp..I do this when I"m writing a review and click to another page for something..When I click back to bandamp  everything  I have wrote for the review is still there..also the copy and paste is a good idea as           
Puppet stated..
Flyer