Re: Sony PRS-T1 reboot cycle
Even I used to face similar kind of problems on my Ebook reader. So, I just left my e-reader all alone and stopped trying to reset it or either pushing any other buttons or stuff. The next day in the morning I saw that the rebooting problem had stopped and then I did a complete shutdown of my ebook reader and restarted it again. Now I am not facing this problem any more, so try to follow my steps and see if it solves your case.
Re: Sony PRS-T1 reboot cycle
I used to have this problem and I found out that this was happening due to some poorly formmated book which was loaded on my SD card. So, after removing this book solved the issue for me. You can easily find out the problematic book by loading few books at a time. Also, if you have too many books in the library and also have setting to show book covers in library then you might face this issue. So cut it down to half the books and also change the settings.
Re: Sony PRS-T1 reboot cycle
Yes, I agree to the above, I was having more than 2000 books in my Sony PRS-T1 ebook reader and it used to freeze when I was looking for books in the library which was set to show book covers in it. So, you can try to change the settings here to read captions with title and author and you wont be needing the book covers setting. You just have to choose list view instead of covers view and your problem will be solved.