Created attachment 2265 Possible fix for the missing tooltips Since GTK 2.16 displaying tooltips in the panel plugin is broken because of changes in GTK. This happens at least when the plugin update timeout is set to less than 500ms. I described the problem a bit more detailed in bug #5175. Attached is a patch which fixes the problem by adjusting the default GTK tooltips timeout to the set timeout in the panel plugin.
Created attachment 2368 Alternative fix and use gtk_add_seconds if gtk+ >= 2.14 Sets the interval min/max/delta -> 1.0/10/0.25 Under gtk+ 2.14+ displays a label that whole seconds are more efficient, and uses g_timeout_add_seconds() if whole seconds instead of g_timeout_add(). Also updates tips to use the 2.12+ API, since GtkTooltips are deprecated from almost two years now.
I'm using gtk+-2.16.6 and without the patches, the tooltips will never show. For me, the first patch by Enrico completely fixes this issue. Thanks for this solution, I've fixed the other plugins this way. After applying the second patch the tooltip shows when there is no network activity. If there is activity, the tooltip never shows up.
Thanks for the patches. Ultimately though, I applied a different solution, and switched from the deprecated GtkTooltips API to the newer GtkTooltip (without an s). This solves the problem.