I've just found a bug with pagination and random ordering. If you turn random ordering on and you have more than one page you might never see some of the items in the category.

It seems that at each page the system randomises the items again and again rather than randomising initially and storing that list between pages to ensure all items are shown.

For example if I had 6 items called item-1,2,3,4,5,6 and the order was set as random with 2 items per page this could happen..

item 1 and 6 on page 1
item 6 and 2 on page 2
item 3 and 4 on page 3

in this instance item 5 would never be shown and item 6 is shown twice.