[GBA]

I have used Calibre for several years for cataloguing, organinsing and editing meta-data, and thoughly enjoy using it. However for the last week or so when I try to view a book instead of swiping on the mouse (left or right) to turn the page I have to use the left or right arrow keys and the books go from top to bottom, rather than left to right (like a normal paper book would do if one turned the page), and like a pdf book.

Is there any reason for this and is there a way of reverting to the old way of turning pages from left to right and not top to bottom?

Many thanks for those who may have an answer.

GBA