What do red the ticks mean next to the topic posts?

they mean you've look at the post.Gillian

Not that it's important, but I get red ticks on posts I've definitely NOT read...maybe it's just me.... didn't want to look dumb by asking what they meant....

Same here thanks for letting me know!

You are using the 'new posts' link then Try using 'active topics' to read the forum instead. Then only the threads that you have actually opened and read will show the tick.