Problem mounting 1GB cartridges on a 2GB Jaz drive?

Len Levasseur reports that he could not get several of his older 1GB Jaz cartridges to mount successfully on his new 2GB Jaz drive. They still mounted fine on the 1GB Jaz drive. He contacted Iomega about this. They told him that they have received numerous similar reports. "It is under investigation and is recognized as a problem by the software engineers."