Hi Frank,
Yes, it mostly has to do with the version of AEP. Since you have AEP 1.3.2, then you should upgrade to 1.4.3 first, then to 1.6.4, and then you may upgrade to mPower 5.0. Back up your configuration first just in case. Maybe even back up your config after each upgrade. The instructions on the following page say you need 1.4.4, but good luck finding that. AEP 1.4.3 was the version that was released for your Conduit (MTCDT). AEP 1.4.4 was a bug fix release for the Conduit IP67 (MTCDTIP) and other than that it is identical to AEP 1.4.3 (I’ll make a documentation ticket to have the changelog corrected).
http://www.multitech.net/developer/software/aep/aep-firmware-changelog/
If you run into trouble, then create a support case on our web site ( https://support.multitech.com ). There IS a way to upgrade straight to mPower 5, but it involves completely erasing the NAND flash (and thus all configuration changes).
Best Regards,
Darrik