[amsat-bb] SatPC32 Question

Just recently on my last fo-29 pass.. I attempted to have SatPC32 do my doppler correction for me. This is what I noticed.. and I am looking for any Ideas. When I found my downlink freq using the VFO mode the doppler would jump every 5-6 seconds.. not a smoothe tune. and eventually I lost my downlink freq altogether. How often does the program tell the radio to move the frequency? I have it set to the recomended 90 setting.. Im just wondering is this normal.. or should it smoothly tune a ssb signal at all?

-Steve Raas N2JDQ FN20vg