I tried the reset and i waited for a while for the reader to reboot.
Then i turn it on and it was resetted, it asked again for the first configuration steps.
But i did not solved the issue, my recently read area show just thumbnails of pdf.
I have "Homepage preference" set to "show recently read books" and i tried to either set or unset
"show books' tittles :-) instead of their names in library"
here a screenshot.
it's basically impossible to figure it out the pdfs with just the screenshot, for example the one in down left corner.
Best thing will be something like the last icon (tops-20 user's guide is an html)
with an icon partially overlapped by the file name/title