VB6 on Win 7 - problem on rebuilt system

I've used VB6 for some very simple domestic programs for many years, it does the job. For 4 years or so my Win 7 Pro PC has run VB6 ok. I upgraded the PC to an SSD 2 weeks and have clean installed Win 7 Pro and reinstalled all the apps. VB6 installs and runs but... One program has an UpDown control and when VB6 loads the project I get errors on load and a log entry saying "Class...