I've run across a few ASP.NET based issue tracking tools. Here's a list of the best ones I found:
Gemini [CounterSoft]
This is a lightweight, but powerful issue tracking tool. It has a very simple install, and a free license option (up to 10 users, and only on an internal server). The full enterprise license is just $280. I set this up at Assisted Solutions and Data Research Group, and they have been very happy with it thus far. It has a few quirks, but supports all the main functionality needed in an issue tracking tool....