I have an issue. This get's frustrating but I'm sure it's something simple. I imported an AI path into max and want to bevel or extrude it to make the shape fill in. It is an outline of a dear head. When I try to ad an extrude, or bevel modifier it works along the "sides" of the spline instead of filling it in make a solid object. I hope this makes sense. Another example is when I try to convert it to an editable mesh or poly it disappears. I've gone to the verticies of the spline and made sure none are interfering with one another, I've changed to bezier curves and tried to get them smooth. Just not sure what I'm doing wrong. Any ideas?
One question: are you saving your Illustrator file as a legacy format? You have to make sure your save your file as Illustrator 8, or the earliest version that's available on your version of Illustrator.
Not doing this is the cause of most of the AI spline problems in Max. If you're still having problems, try scaling your spline up about 1000 percent once it's in Max. You can sometimes avoid this step by putting crop marks on your file in AI before you export. Good luck!