This MAY be, MIGHT be, a Firefox bug that was opened 14 years ago and since reopened. I lack the energy or interest to follow up.
Bug 363840
IFrame on refresh of page, does not show the correct content.
May have something to do with me using Windows 7 and why it isn't seen more. Or unique to BBS and a few others. Back on the day it wasn't unusual for a clever boy to write nonstandard code to gain some performance advantage. Or choke the rendering engine with the unusual code. Might be something like that. It's a damn nuisance anyway.
s not
