Can't get to next page of invoices

Can't get to next page of invoices

I currently have 68 invoices, displaying 50 per page. When I use the paging button (or the page 2 link), I am *not* moved to the next page -- nothing happens. If I change the settings to display 100 per page, again, nothing happens.

This also appears to be happening with other lists. I only have 45 customers, so I can't test the paging, but if I try to reduce the display to 10 per page, nothing happens.