When you log into your Windows Azure VM which has Windows Azure Web Role, you might have problem accessing IIS logs. When you will try opening IIS logs folder you will get "access denied" error. The irony is that this issue happens randomly.
IIS Logs Location:
Here is what you can do to access IIS log:
Trying to understand this better, when you say the issue happens randonmly are these intermittent/happens when when the instance is deployed newly or a IIS configuration or some change that triggers this issue? are there any classifications of symptoms for the problem that would help analyze the situation and take appropriate action pro-actively, any suggestions/ pointers would be of great help.