ALV to Excel problems

HI

I have created an ALV report with 87 fields in it. Whenever I am trying to download that report into excel the number of column breaks into 2 rows. In this case, The downloaded file contains 57 Columns in 1 row and remaining 29 Columns in second row. Can anyone please help me in understanding why this is happening while downloading this report into excel file and what will be the solution to correct it.

Thanks,

Sreekanth.G