Windows Azure: There Is Currently a Lease on the Blob and No Lease ID Was Specified in the Request Fix

If you have this problem, then you are using a tool such as the Azure Storeage Explorer to try to delete a blob. Here is the simplest way to fix this:
 

1. Go to your Azure Management portal.
2. Click Virtual Machines.
3. Select the name of a virtual machine (VM).
4. Click Disks. A list of OS and data disks will appear. If you have deleted a VM, you will see a corresponding OS disk and any disks you had attached to the VM.
5. Delete the now extraneous disks. Click the disk, and click Delete. Use the option to delete the associated VM.

If, for some reason, this does not work, you can try to use the procedure shown here:
http://social.msdn.microsoft.com/Forums/en-US/WAVirtualMachinesforLinux/thread/baf1040b-baf8-47d2-a69d-56f9fc265abf