Gantt Charts were working decently with 2.0.2, after upgrading to 2.0.3, I get that common error:

"Your are trying to use the locale..."

I am reverting back to 2.0.2 for now, as it seems to be pretty stable for me.

Reference to this post:

http://www.dotproject.net/vbulletin/showthread.php?t=5177

I was able to fix my issue and stick with verison 2.0.3 by using the file found in the above post.