I've had a similar problem.  I'm using an Altek AC30 with both GRASS and 
LTPlus.  I believe mine is because my office is located near our power backup
system.  Moving the digitizing board 10 ft. away from the UPS minimized the
problem.

Is the UPS nearby?  Maybe the main power feed for your office?  The magnetic
radiation from them could be the source.

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Bruce Nielsen                     VOICE(net): (317) 290-3203
Computer Specialist (GIS)         FAX(net):   (317) 290-3225
USDA-Soil Conservation Service    INTERNET:   bnielsen@in1000.attmail.com
6013 Lakeside Blvd.
Indianapolis, IN 46278
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Thoughts, feelings, opinions, etc. expressed here are my own and do not
necessarily reflect those of my employer.


