watin nunit UnauthorizedAccessException : Access is denied

I've started having trouble running Watin tests via Nunit. Last week this was working but this week it's not. I'm not aware that I've changed anything but I've started getting UnauthorizedAccessException : access is denied errors being raised when I'm trying to click a link.

The simplest code that raises the error is as follows:

[Test, RequiresSTA]
public void TestTest()
{
  using (var browser = new IE(SMDTestConfig.TestURL + "Game"))
  {
    browser.Link(Find.ByText("Log On")).Click();
  }
}

The full error message from NUnit is as follows:

SMDTestFramework.GameTest.TestTest: WatiN.Core.Exceptions.ElementNotFoundException : Could not find A element tag matching criteria: Attribute 'innertext' matches '^ *Log\ On *$' at http://localhost/smdci/Game (inner exception: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))) ----> System.UnauthorizedAccessException : Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

The error message would suggest that it's the Find.ByText("Log On") statement that's causing the error but if I split it up into 2 lines as follows:

AttributeConstraint cons = Find.ByText("Log On");
browser.Link(cons).Click();

The error is actually raised on the second line.

I've looked at the following questions but none of the answers seem to work for me:

WatiN UnauthorizedAccessException errors

Access denied error ( Visual S开发者_JAVA百科tudio and WatiN )

UnauthorizedAccessException when redirecting to a new page with the error displayed on top

Getting around System.UnauthorizedAccessException : Access is denied