This is basicly the bug #126461 described in gnome bugzilla (see url) I don't know if this patch works well with libgtop 2.0.6, so I include a ebuild for the new libgtop 2.0.7 (should be a simple version bump).
Created attachment 21465 [details] New gnome-applets ebuild
Created attachment 21466 [details, diff] gnome applets multiload memory display fix
Created attachment 21467 [details] new libgtop ebuild
patch applied in gnome-applets-2.4.1-r2 . libgtop 2.0.7 = 2.0.6 + gentoo patch, so no need to bump. thanks for your report.