We have a loan where there are two co-signers. Instead of signing the actual note, our system produced a separate Notice to Cosigner listing loan amount, loan date, etc that they both signed. Does this suffice, or do they need to sign the actual note as well?

Did you read the Notice To Co-Signer being produced? If it follows the model form I'll bet you'll find a sentence that reads, "This notice is not the contract that makes you liable for the debt."

Unless you have a very unusual and legally binding Notice to Cosigner Form then most likely none of your loans that you thought had cosigners do because you most likely did not have them sign any legally binding contract.

That sentence is at the bottom. Looks like they need to sign the note. Thank you.

You may want to review your "co-signer" loans. If none of them have signed the note then they are not legally obligated to repay the loan (check with your legal counsel). If they are not legally obligated to pay the loan and you have been reporting the loan on their credit report then you may have additional legal/regulatory issues (again check with your legal counsel).