GMON Data Upload Failed

Hi,

I am new to profiling NIOS II software. I followed the checksum acceleration example and wanted to see the results of gmon.out. However, I got the following error. This error is even after I use a usleep(500000000) statement just before the return from the main function. I am using a DE2 board with 50MHz system clk. Can someone please suggest a fix? Thanks in advance.

running target program until exit

uploading gmon data: 0%75%75%75%

gmon data upload failed

leaving target processor paused