Any clue why this might be happening?
When I reach about 27 rows, visitors to the blog see a blank page - i.e. the main page content above the comments is blank. There is nothing within the content divs. Logged in users see the content fine - unlimited rows.
Within each row I've got a twitter shortcode and an icon shortcode - but I've done some limited testing without these and find the limit still there, although I might be able to get a few more rows without them. Also, I changed the theme with the jQuery UI plugin.
I could do more testing, but I thought I'd write first to see if any of this was a known issue and perhaps, hopefully with a simple solution?