After several hours, posts and attempts to figure out a way around this problem I finally had to give up and try another self hosted cart script. I spent a lot of time in CubeCart and there are a lot of things I love about it but I simply cannot hand off a store to my client with this behavior, bug or whatever it is.
I would suggest a fix for this problem ASAP and after that a PayPal donation link for the developer. In my opinion, technical support cost might be too high or not needed for most folks but I for one would certainly consider a donation for this great free script. Just a thought.