In Unity Indie I cannot get the lightmapping to work when I plant more than about 20-30 trees.
Is it running out of memory. I have 4 gig and I guess this is just how it is, rather than a functional bug. It gets to a certain point through the procedure and either quits, or the program closes. If I reduce trees, it works.
No, that sounds like a bug, although we’ve had no issues here baking terrains with a lot more than 30 trees on them. And with this it shouldn’t make any difference between Indie and Pro… we’re not arbitrarily capping the number of trees that will bake shadows in Indie 
If this is 100% reproducible please file a bug report.