special characters being converted or not linking

Hi, I sell sheds on my website and I use keywords like:

6′ x 8′, 8′ x 10′, 8′ x 12′

when I type those into your keywords they get converted to this:

6&# 039; x 8&# 039;, 8&# 039; x 10&# 039;, 8&# 039; x 12&#0 39;,
but with no spaces and the links don’t work.

So I typed the keywords into Microsoft word first then cut and paste into your keyword.

This time the text remains correct but no links are generated.

Any idea? Am I doing something wrong?

Thanks,

Geoff

http://wordpress.org/extend/plugins/seo-auto-linker/