Plants disappear when using regenerate

Hi,

My workflow is max>D5, and sometimes i m hit with the regenerate prompt, mostly due to small adjustments made in max. however, very often when i hit the regenerate button, my plants which have been placed with brush scatter, disappear. And there is nothing i can do to get them back. I have to redo them over and over again. I cannot even save the area

This is my first large project being done in D5, i like it so far, but there is no way to have a real workflow like this.

What is the solution to this issue?