larger posts wont show..?

Hi, whenever I come to create some content, be it in bbpress, buddypress, a blog post or even create a new page, it all seems to work fine provided it’s relatively small, say 4-5 lines.

However, when I come to create a larger bit of content, say like “forum rules” that is clearly going to be over the 4/5 lines, it shows a blank page/topic/post etc. but then clicking edit shows the content is there and should be displaying.

now I have checked the comments and they seem to be working spot on, be them large or small…

so I am wandering if anyone has any idea what this issue could be and how best to solve it..?

If you wish to test it or see what I mean for your self then;
My website is:
https://www.CarFreaksUnite.com
and you can log in using:
USER: WP Help
PASS: WP HELP

Thanks in advance.