My application appears to be back in the game, after some corrections to my url encoding. I've posted the code here (http://dpaste.com/hold/ 72568/) for the benefit of other VB.NET developers.
This is a VB.NET port of the URLEncode method found in the Twitter/ OAuth class from Shannon Whitley and Eran Sandler. They rock. Hopefully, this gets you guys back in the game as well.
