Created attachment 5730 
patch to fix the problem

Currently the default tooltip is broken.
In main.c:226, it says
acToolTips = g_strdup_printf (acToolTips, "%s\n"
            "----------------\n"
            "%s\n"
            "Period (s): %d", poConf->acTitle, poConf->acCmd,
            poConf->iPeriod_ms / 1000);

But it should be
acToolTips = g_strdup_printf ("%s\n"
            "----------------\n"
            "%s\n"
            "Period (s): %d", poConf->acTitle, poConf->acCmd,
            poConf->iPeriod_ms / 1000);
The first argument of g_strdup_printf is 'format', so the current call is incorrect.

Patch attached.