Ann: Quarterly Results Update, page-6

Stephok I think you are correct in assuming that the lease should have started. I think from the announcement the other day it is clear in one of the answers Kevin gave to the ASX that he considers that the agreement (even though not finally signed) is that GBF was leasing the Burbanks Mill from 1st March and that MXR will be charging GBF the lease fee for the month at the end of the month. At least that is what I understand from what is stated there in that Q& A announcement.
It is interesting that the comment in today's update just indicates the bullet point as being "second toll milling campaign completed with a third due to commence early in April."
However that bullet point comment is not fleshed out in the actual text of the announcement in any shape or form as far as I can see.

Now if as seems to be the case GBF has not actually started operating the Mill under the lease agreement from March 1st then the question arises ....Why not ? Does it indicate some problem at GBF with having sufficient feed stock to supply the Mill from Comet Vale ? Are there mining issues at Comet Vale ?
Certainly Kevin is at pains to highlight the importance of how well the Mill has been performing with reliable and constant supplies of ore for treatment through the Mill since mid December. Reading between the lines I would hazard a guess that MXR has made arrangements with some other operations to have their ore toll treated through Burbanks to ensure regular supplies. I may be wrong but that is what I would guess from how things appear to be worded.
However there is still the strong statement that the agreement is close to being signed off (bullet point) although nothing is really said about that in the main comment section.
Wording in the second last paragraph on the second page is also interesting.