Hi Benoit,
I have no solution for you but I would like some explaination.
Does it happen all the time or randomly?
Does it only happen when you make a call with do Form?
I'm asking because I have seen a similar situation where an application is hanging once a a while without no visible reason and I'm looking for a solution since two weeks. Maybe we can share information.
Take a look at microsoft support articles for Q183522
Good luck.
Diane Robitaille eng.