I'm tentatively calling this as fixed after reformatting* my epubs using Calibre, and getting a >95% reduction in page turn problems during a 6hr reading session last night with my Glo. Also just tried the same fixed files on my Touch and again, almost no problems.
Seems like it was bad epubs then and not the device itself.
Thank you for the help everyone
(* when I say reformatting, I'm just talking about using 'convert books' with the kobo reader output profile selected in page setup)