If you find out, please post the solution here. That feature has bitten me several times.
I don't think there is a way to turn it off. At least not from the system options menu. You may want submit an SPR to solidworks. Good Luck !!!
Not sure if there is registry file hack to do that.
The real problem is that SW bounces focus around. Ex:
1. Select fillet tool.
2. Select your radius.
3. Move the mouse over to the model.
4. Scroll to zoom.
<<Four scroll clicks zoom in, but the fifth one indexes your radius value by 0.1">>
5. Wait for preview to fail (up to 1 minute).
6. Change radius back to your intended value.
Scrolling to change value is stupid, but it isn't malevolent. Bouncing focus around so your clicks and scrolls are totally unsupervised is the part SW should be ashamed about.
Still no fix? This is goosing me a couple of times a day. Nothing like having a hundred edges with 0.2 mm fillets go to 10.2 mm fillets, and then having SolidWorks sit 5 minutes trying to make it work.
Everyone please vote for SPR #: 801432, at