on 25/feb/2008 i cleft grafted a myer lemon on an unknown orange tree.
yesterday 31/mar/2008 i tried to remove the polythene bag slowly were i noticed it had a bloom. that is strange?
here are some picture but it seems unclear because i took the photos from my mobile:

Not strange at all. I have had a lot of my bark grafts that bloom as soon as they break and a few of my T-buds-- I had one T-bud that produced 3 grapefruit in the first season (this year it did not bloom).

I think it would be good for the graft to remove the flowers so it can concentrate on vegetative growth instead of fruit.
That's what I did to my clemenule.
I have a bunch that flowered but I clipped them. Not only on my citrus but other plants as well.

I think it depends on the situation. If it is a seedling that you are grafting to make a new tree, I would definitely remove flowers.

If it is a cocktail tree that you have added a new variety to, you may want to have the fruit. I grafted 3 varieties of grapefruit onto my lemon tree in the fall of 2006. I forced them in the spring of 2007--one of 2 ruby red grafts flowered and produces 3 nice grapefruit on a 6 inch sprout. The other 2 varieties and the other ruby red did not flower, and most of them grew about 12 inches last year.

This year none of those grafts flowered--they are all putting on a lot of new growth including the one that produced fruit. I had one mystery bud that broke after a year and a half-- it is obviously a grapefruit and it is flowering--if it sets fruit I will let it develop.

I guess this is to each its own.
I had one pomello that fruited but died the 3rd year. It did not grew at all the 2nd year. It just withered and died on the third.

I had one fomoko orange grafted unto a Eureka and it fruited the first 6 months and I harvested the fruit but it stayed the same size for 2 years . It is just now growing vigorously after the 3rd year. Luckily there was no flowers or fruit for 3 years now.
Someone said that in grafting, if you let just one fruit stayed on the tree you are taking away 4 feet of growth on that branch . I am not sure how true that is.
I also have a Prince Ranier Cherry grafted on a Stella Cherry, After a few weeks you could only see flowers on that graft branch, then turned into fruit and I harvested that when riped. They were very good eating. But the whole branch died afterwards. It never sprout any leaves.
Oh, I have many more experienced that I can tell and experiencing right now but that's all for now.

thanks for the sugestions but i dought that the flower will hold and not drop off.

i did not intend to graft i just had an extra bud wood so then decided to graft. i'll try keeping that tree a cocktail tree but i fear the taste of friut will change.

The rootstock can influence the flavor of fruit, (lemon rootstock in particular will reduce the quality of other fruits but increase the juice) but I do not think orange will flavor your Meyer that much (and of course the Meyer will not influence the taste of the orange).