Rounding of "Optional Dimensions"

For example, if you create a molded body inductor and then fill in the manufacturers recommended footprint dimensions S, L and W but leave L1 and W1 unfilled (because they are "Optional"). L1 and W1 will be filled in with rounded versions of L and W. You end up with the two pads having very slightly different dimensions.
If you copy (duplicate) L and W into L1 and W1 dimensions, then the non-rounded dimensions are remembered.

I only noticed this because DipTrace currently will only import PADS components where all the pads are the same size.

Jeff.M wrote: The dimensions are only optional when youre calculating the footprint. As soon as you check the 'Use Mfr's recommended..." box you're overriding the calculation and forcing the use of whatever values are entered in each textbox adjacent to the referenced dimension.

Sorry I misinterpreted what happened.
When you create a new component (eg molded body inductor), and you first click on check the 'Use Mfr's recommended..." box, initially none of the values are filled in (blank boxes). I filled in S, L and W and left L1 and W1 and pressed OK. The program then used the filled in values, and used calculated values for L1 and W1. By coincidence in my case the difference between L,W and L1 and W1 was what you would expect if the values had been rounded.
It helps stop stupid errors, if when you create a component you click on OK before checking the 'Use Mfr's recommended..." box, so that the values are all filled in.