EDIT: correction, you already did transfer them to pc

just done same test and sure enough i got identical error

EDIT2: quick google around indicates that problem is wide spread with windows photo software, issue reported on vista and win7 all over the place, there is tones of solutions but so far i didn't run in to one that would work for me.
it seem to be only acting up with photos that have some extra tags (n900 does add some tags i understand) so that explains.
photos from my normal camera open and save just fine in windows photo software