Sorry, I said the wrong name. It's the dialog you get with list_tags, which lists the tags in the current file. I think it's bound to Alt-, in the default VSlick install, but you can get it with list-tags from the command line.
To demonstrate the problem, start with something like this C# file, although any class works:
class testClass1 {
void _MethodWithUnderscore() {
}
void NoUnderscore() {
}
}
Execute the list-tags command, and the cursor will be frozen on the _Method... line as you type. If you move it down below the last method that starts with an underscore and start typing, then it finds the appropriate method easily.
Now remove the underscore from the first method, and you'll see that it navigates correctly as soon as you open it.
I never noticed it before, but I just got class support in a language where I couldn't get it to work before, and started seeing it. This language has magic methods that start with __ (e.g. __New is the ctor), so I have them at the top of every list. It's pretty annoying because that dialog is my main method for navigating around in my file, and all of a sudden it doesn't work right. I could figure out the problem if I need to... I was just hoping it was a known problem with a solution.