I'm having a problem getting the ILS to track the GS  successfully.  It tracks the localizer okay but, when the GS locks on, it is sluggish and erratic at best. It appear to track, then lose it followed by excessive rates of climb or descent.  All indications [ Lights] show a lock on of the GS.
I believe I'm familiar with the procedures to use with ILS.     I love this A/C even with this Glitch.  Anyone got any ideas what is wrong, or is it just finger trouble.