anyone else having this problem?

Yup you can't post in that area... you need to post in any of the separate cashback areas in the area above.

If you have a new cashback site, post about it in the Misc reward and cashback site area and maybe Frugaller will create a new subtopic for it within the 'Further cashback...' section.

Or if it's just a reward site, post it in Interesting Sites as you can put referals there.

D