harryberlin has a plugin that run and not me !!!! Booooooooooooo
There is no real problem with VB6 and win 8 (or win 7)
The main issue is usually a matter of permissions.
Make sure regsvr32 is run with admin permissions (Right click runas)
I usually put it in a bat file.
The other difference is regsv32 has to be run in the same directory as the dll you are registering or you have to include the full path to it.