Issue when sending data to Excel in Nav 2013 R2

Hi Forum, has anyone come across an issue when sending data to Excel in Nav 2013 R2. One of my clients has noticed that when they send a Production BOM to Excel using Cntl + e data is duplicated in cells. For example if there are 7 lines on a Production BOM and the 4th line has a Starting Date specified of 01/11/14. When this is sent to Excel, all the lines from the 4th line onwards have a Starting Date of 01/11/14 even though they were blank. I have tried this in Cronus Nav 2013 R2 and get the same issue. I couldn’t find anything on Partnersource so I was hoping someone on this forum had come across this and knew of a fix. Many thanks Paul