Re-reporting trac-153. The following was true of 0.82.1 - apologies if this is already resolved.

Steps to reproduce:

1. Insert a part. Note its position and rotation is specified by integers
2. Translate said part using the drag tool. Note the above, as before
3. Rotate the part 90 degrees. Note that the rotation field doesn't
   display integers
4. Translate the now-rotated part. Due to the non axis-aligned rotation,
   the position has also gained small fractional parts

Some possible fixes:

• Generate more precise rotation matrices for common rotation angles
• Round matrix elements to N(~=5?) decimal places
• Provide a "resnap selection to grid" button (fixing item 4. This
  wouldn't have a meaningful way to fix item 3)