Hi Geirmund and welcome to the Forum! Thanks for providing your HW&SW details. And you also checked QuickGuide first, good!
To be honest, I haven't tested old ReAction GUI programs for OS3.9 with new the ReAction GUI included with OS3.2. Therefore I don't really know whether those two toolkits are compatible with each other. But I assume they are.
Anyway, yes, it's a good idea to copy the resource.library from OS3.9 to OS3.2. I've never done it myself so please let me know whether it helped.
Btw. another reason might be missing .gadget (see below) but I think all the required gadgets are in place (otherwise the VirtualCD would not work on OS3.9 either) http://www.gregdonner.org/os39faq/installtips.html#20