Cannot attatch attribute features after update to 1.5.1

[znowflake]

Since I have updated my site to 1.5.1 I have not been able to feature new products on my site.
I can add the images and descriptions fine, but when I attempt to add the attribute features and insert, I am just returned to the main admin page every time.
I have also tried to add a new attribute in the name manager under catalogue and the same thing happens, I am returned to the main page
I am at a loss and would appreciate any help

Many thanks in advance

[DrByte]

Sounds like one or more of your admin/*.php files is still from the old version.