Delegate.CreateDelegate ArgumentException not helpful!

Question

I have some code that is supposed to return a delegate of a certain type:

private static RuleSet.RuleDelegate<MemberType> _GetMemberRuleMethodDelegate<MemberType>(string methodName, Type ruleType)
        {
            MethodInfo mi = ruleType.GetMethod(methodName);
            if (mi != null)
            {
                if (mi.IsPrivate)
                    throw new FastReflectorFailException(String.Format(
                        "Rule: '{0}' is private, and cannot be executed directly.", methodName));
                return (RuleSet.RuleDelegate<MemberType>)
                        Delegate.CreateDelegate(typeof(RuleSet.RuleDelegate<MemberType>), mi);
            }
            else
                throw new FastReflectorFailException(String.Format(
                       "Rule: '{0}' does not exist.", methodName));
        }

The idea is that I grab the method by it's string name (methodName), from the Type ruleType. It gets a MethodInfo object, and if the method isn't private, it tries to return a delegate of type RuleDelegate<>, whose signature the methodInfo variable matches (I know for certain it matches because this is a limited test case).

On this line, the code throws an ArgumentException error:

return (RuleSet.RuleDelegate<MemberType>)
                        Delegate.CreateDelegate(typeof(RuleSet.RuleDelegate<MemberType>), mi);


It says "Error binding to target method." Thanks, I can see that.

Anyway, in the metadata of the CreateDelegate method, I found this note about ArgumentException:

        //   System.ArgumentException:
        //     type does not inherit System.MulticastDelegate.-or-type is not a RuntimeType.
        //     See Runtime Types in Reflection. -or- method is not a static method, and
        //     the .NET Framework version is 1.0 or 1.1. -or-method cannot be bound.-or-method
        //     is not a RuntimeMethodInfo. See Runtime Types in Reflection.

I don't know how to tell whether the type inherits from System.MulticastDelegate.
I don't know how to tell whether it's a RuntimeType (but I suspect it is).
I'm using .NET 2.0, so that's not the issue.
I know why the method would be unable to bind.
I know how how to tell whether the method is a RuntimeMethodInfo.

I looked at "Runtime Types in Reflection" on msdn, and it's worthless.

Can someone point me in the right direction?