Problems with Attributes not acknowledging their presence

I keep getting the following error message

Please correct the following:
On the Option for: Ribbon Size You picked an Invalid Selection: 4mm

This occurs on every option I have set up. I'm using 1.51 at the moment but haven't a clue as to why my options/attributes aren't being accepted.

What are your settings in the Attributes Controller for this Product on your Attributes? Could you do a screen shot?

Ajeh:

What are your settings in the Attributes Controller for this Product on your Attributes? Could you do a screen shot?

587 Ribbon Size 4mm + 0.0000 + 0 1
Display Only Free Default Discounted Base Price Required $0.00 $0.00

It is one of three attributes, everything is set up according the way it was set up in 1.39a (my old site). I'm on 1.51 now (and am considering upgrading to 1.53 real soon)

I was reading some recent post (sorry can't find it now) where the suggestion to upload a template which controls the attributes from default into the chosen template file (as it might be the templates fault) but as I said I can't find it again to know which file and where to put it.

On the:
Display Only

Are these set to a X or is the icon yellow?

Ajeh:

On the:
Display Only

Are these set to a X or is the icon yellow?

The ICON is yellow

The bar beneath which has detail about Used for Display Only is set to Yes. It says Attribute Flags ... I'm not what a flag is. Is that the problem?

Ok I switched it and it worked, phew. Now why would the template have that switched on as a default? It makes more sense for it to be shown in order to work.

When an Attribute is marked as Display Only, it cannot be selected and added to the shopping cart ...