manufacturers and characteristics not syncing up!

Hi,
I have different artists setup as manufacturers. I have the module "Also by this Artist" set as the under product page module. All works great until I add a new product and add a characteristic, like "size". When I add a new product without a characteristic the correct manufacturer is under the product page but when I add a characteristic to that same product the wrong manufacturer is under the product module. This problem is intermittent. Any ideas as to what might be going on?
Thanks

Hi Mel,

Can you show me some screenshots of how did you configured :
- Your product page and your product's variant page
- Your "Also by this Artist" module configuration page

It would help me to determine from where the problem is coming from.

Thank you.

Here are the screen shots. One without the variants added and correct product, one with variants added and wrong product, and the "Also by this Artist" module setup.
Thanks for your help.