Manufacturer/Category Filter

I am using Zen Cart 1.3.8a

My Manufacturer / Category Filter works fine on the manufacturers_all_product page.

What I am trying to do:
I would like to insert that filter (drop down select form) into another page.

What is Happening:
I have managed to do so but when a category is selected (clicked-on) it directs me to the shopping cart page.

Any suggestions to why this is happening?
Anyone know of a simple way to call the feature on a different page other than the manufacturers_all_product page?

Any help would be great!
Thanks

O k maybe i didn't or can't explain it any better. Here is a link to a product info page that I have added a manufacturers category select drop down form to, I am manually entering this and uploading it via easy populate.

I want to know if there is a way to call the manufacturer/category filter feature drop down on on a product_info page. This way when i update categories I don't have to manually change every time.

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