[Inkscape-user] Illustrator complains about too many nested groups

Hi, One of my colleagues would like to use Illustrator (Adobe CS6, i think) to edit some SVG files I created with Inkscape, but Illustrator complains about there being "too many nested groups". Any hints on how I could "fix" the SVG? (Perhaps I could convince him to switch in Inkscape too, but well...) Thanks in advance, Antony