Problem: Values disappear from INFO tables after making changes
Saving edits to an INFO table, after making two or more calculations in ArcMap, causes values to disappear from the table.
This is a known issue.
Solution or Workaround
If the table is a standalone INFO table, convert it to dBASE format. If the table belongs to a coverage or it cannot be converted, try saving your edits after each calculation to avoid data loss.