It wasn’t only the iBooks. I’ve come across a few 15 and 17 inch PowerBook G4’s which had the same stale sweat smell as the iBook G3.
I was entirely unaware of the olfactory phenomenon until this year.
And it also helped to explain why my 17" DLSD vaguely smelt of body odour when I got it. It wasn’t anywhere as strong as other testimonials here and elsewhere online, but it was noticeable enough (and novel enough as a cameo in my home) that I pondered whether the prior owner was a stinky dude (turns out the prior owner
was a dude, but that discovery is another conversation).
Thing is, it's always open and running, and I don’t generally smell it much anymore.