version is 8.0.1087 001. I seem to have fixed to problem by starting a new solution to clone the broke one with a lot of add existing item. If you are interested, the problem in my post is just the last chapter in the solutions' decent into madness. This is a solution to contain the general interrogation and navigation for a Siebel we app, using the Siebel libraries.
First, attempts to interrogate targets started throwing exceptions on occasion.
Next, the first thing happens more frequently, requiring a restart of VS every time, and matching becomes extremely slow.
Next, changes to an automation would sometimes cause VS to claim that a build failed, though no error message was provided.
The title problem and intensification of other problems mentioned followed and the solution became completely unusable.
If it matters, the web app has over 500 controls, almost none of which are matched with ID. Thank you for your help, I am very interested if you have any insights into these shenanigans.