New measured grids have labels that default to 6 decimal places. The vast majority of people make maps that are at a scale such that 0 decimal places are required. This has bugged me for as long as I have used ArcGIS.
To change the number of decimal places, it's necssary to take the following steps:
1. Data frame properties
2. Grids tab
4. Labels tab
5. Additional properties
6. Number format
7. Number of decimal places, set to 0.
This must be done with every new grid that is created.
Please consider either changing the default value to 0 (from the current 6), or allowing the user to set it permanently to a user chosen value.