The G3 B&W and the DV iMac are from about the same time... why would one recognize it properly, but not the other? Just to be safe, I'm holding on to the RAM I took out of the iMac, just in case those 256mb modules ends up causing problems later on.
When I was hunting for parts, I basically got to the point where I was just grabbing RAM before the rain started up again. It's not really that big of a deal that my tower didn't like them... it's just that I found it to be odd. Sorta ruins my chance to max out my B&W with 4x256MB like I had hoped, but for free, I think i can deal with it. Having 3x256MB + 1x128MB is still a lot better than what I had in it before. I'm just glad that those RAM modules worked properly in something we have here right now.