I noticed the other day in Motor Tuning something odd.  When I use the up or down arrow keys my axis is not moving smooth.  It instead is moving in jerks. It starts, stops, starts, stops.  It appears to be a repeatable pattern.  I did a search and saw another post and its final solution was to do a clean install of windows.   So I did that.  I figured it to be a good idea as I had automatic updates on before.  Now I have automatic updates off, a nothing else installed.  However, motor tuning is still doing the same thing.  The fresh install did clear up a problem I was having before with the steppers overdriving missing a lot of steps on certain programs.  The motors jog fine, sound fine, run fine with the gcode it is only motor tuning.
My os is WinXP
Mach version .57
Kernal Speed 45K tested to 60K listed as System Excellent
Using the same profile as before
So my questions for you all is "What can cause this problem?  Can a profile get corrupted?  Are there other settings that can cause problems with Motor Tuning?"
And most importantly,  Thanks for the help!

The only part I can answer for you is that yes a profile can become corrupted.  If you suspect that it is corrupted, you can change the extension of that profile to something like .bak then check in C:\Mach3\xmlbackups if you installed to the default folder and locate a file with your profile name with a date you know was working, copy it to the Mach3 folder and change its extension to .xml  . That should fix it if its the profile causing your problems.

John

Thanks John.  I will try that.

Ok, I tried using a backup.  Still does it.  Tried using a new profile.  Still does it.  Tried switching to the Rosewill 304 parallel cards.  Still does it.  Kernal speed holding steady at 44863.  I have not used motor tuning since upgrading to 3.043.057 from 3.042.022.  It worked in 3.042.022.  I think I may upgrade to 3.043.066 or I would like as an experiment try to install 3.042.022 but how would I manually uninstall the driver?

Upgraded to 3.043.066 and it works again.