Just installed (very quick and easy so well done on that)
Just running through some tests, when an end user logs in with an email and ticket number the first screen fails, however on refresh the page loads correctly.
Try for yourself..
http://www.inc1973.co.uk/support(http://www.inc1973.co.uk/support)
Email: mike.barrett@consultant.com ; ticket Number
There is also a definite delay in returning the error page
Now the error page has loaded just hit your refresh button and you're in...
I've just requested that Fasthosts show error messages to the browser in IIS so this may help