Hi,
On another thread, which I can't find right now, I complained that my Reader would hold a charge for only two or three days.
Now I think I've found a solution. Four days ago, after recharging the reader with the AC adaptor, I left it plugged in because I had added a number of books, and wanted to check out my extensive collections without running down the battery. I left the 505 plugged in all day long, while I periodically checked it.
I had put in a new memory card, switching from a Sandisk 1 GB to a Sandisk 2 GB.
After the Reader was plugged in for around 9 hours, I unplugged it and began to read. Now, four days later, I still have all four memory bars showing!

This has never happened since I bought the 505. I have not shut the reader off with the software during this time, but simply used the on/off switch.
Since the memory cards were both the same brand, I don't think that was the reason for the renewed battery life. I think what happened was that the Reader never had built up a full charge previously, even though the light had duly gone out and 4 memory bars showed.
Anyone have any ideas about this?
It may be a fluke---but I'm hoping it isn't. A number of people have complained of low battery life on their readers, and I'm hoping this might be an answer to the problem.
Starfish