Weird issue with Structure Free

[barstool719]

While using Structure Free to play loops, I found that if I draw the notes on the grid, (say 2 bars for each loop), whenever it gets to the beginning of the next note, it's like the velocity goes way up and the first beat hits really hard. If i change the velocity, it makes the rest of loop sound to light. The weird thing is, if I set the sample buffer for 64, this goes away and the loops play evenly. If it's set for 128 or higher, the hard initial hit is back.

Anyone else had this problem?