problem with projected 3D curve in sw2004

I doing a 3d tube model similar to many others I've done before, but this is one of the first in sw2004. I tried this in sp3 & sp4 with same results. I do quite a few tube layouts this way and I'm worried that the 3d curve function may be glitchy in sw2004. Curve1 would usually be used for a 3d sketch with fillets, etc to make a swept tube. As the file looks now, the general 3D form of Curve1 is a U-shape with downward & inward pointing end segments. While editing the 2d sketches used for projecting Curve1, I noticed some failures (there's actually a bunch of ways to make it fail, but I'll describe only one). In Sketch1, there is a line segment in the lower right that is controlled by a

19° dim and a 12.5" height. If the 12.5" is reduced to 12.25", Curve1 fails, with one of the seqments basically disappearing. There is a 16.662" driven dimension on the same segment. If you make it driving, along with the angle, increasing the angle will cause the same failure. I've used this method with many small variations on about a hundred models before (pre sw2004) and never seen this behavior. 3D sketches also seem to have a new behavior where fillets frequently lose tangency and other constraints if the projection sketch segments are moved as in this example. But that's another story ... Hopefully this model will act the same way for somebody else. I got the same thing on two different machines. model file is at: if that link doesn't work, look in the "Docs" folder at snipped-for-privacy@sbcglobal.net

thanks Bill