AutoCAD Inventor :: Adding Flanges To Contour Roll

I've been having some issues recently with Sheet Metal parts. I am attempting to make a part that looks like this:

The only way I have been able to do this so far is by doing a contour roll to get the rounded part and then add the flanges on as part of an assembly. 

I have attempted to do it as one Sheet Metal piece but I continually run into the problem where I cannot refold the part once I have the flanges.

Here are the steps I have gone through:

1. Created a contour roll to the necessary angle to get my desired dimensions
2. Unfolded the roll
3. Created my hole pattern
4. Folded back the flanges

This is where I got stuck. I attempted to refold the part between the bends but it will not let me do this. If I have one flange, I am able to refold but not when I have 2.

Another problem I have encountered is when I get one flange done, the thickness of it is larger than the rest of the part. 

Autodesk Inventor Professional 2011
Windows 7 for Mac
80GB HDD Partition
Intel Core 2 Duo @ 2.66 GHz
2.75 GB Usable RAM