Three weeks earlier i faced an issue in my MOSS environment.I have an enterprise MOSS farm environment consists of 6 Front-end servers and 5 Application servers. During installation of portal AV solution on these servers, i found that IIS on 5 of these servers were not responding. I opened IIS administration console but nothing was showing. I restarted IIS on all servers but no luck, then i did some research on it and found following MS KB on the same issue
“You may be unable to manage IIS 6.0 by using Server Manager if two threads access IIS 6.0 at the same time”
http://support.microsoft.com/kb/946517
As per this KB this issue is because “two threads access IIS 6.0 at the same time. In this scenario, you may be unable to manage IIS 6.0 by using Server Manager.”
Also regarding SharePoint as per this KB “This problem is likely to occur for the SharePoint Timer service (OWSTimer.exe) in Microsoft Office SharePoint Server 2007. When this problem occurs for the SharePoint Timer service, you may experience the following symptoms:
- In SharePoint Server 2007, tasks that are scheduled do not run.
- When you try to manage IIS 6.0 by using Server Manager, you receive a blank page, or you receive the following error message:
The path specified cannot be used at this time“
There is an hot-fix mentioned in this KB but it is not publicly available, one has to request Microsoft support for acquiring this. I got this hot-fix from my Microsoft account manager within an hour (because of our good relationship with them 
) and had applied it instantaneously. The issue was fixed after this patch and haven’t occurred yet.
I think that this hot-fix will be included in new windows 2003 service pack(SP3) and also might addressed in IIS 6.0 successor i.e IIS 7.0.
