Moving belongings before I move to the US - please help!

Hi,
I am moving to California from Toronto soon, and have engaged the company ABF Upack to ship my belongings in a container/cube, and store it there until I arrive and find a permanent place. The container is supposed to go before me.
I am currently in the process of getting the L1 visa - company transfer. I expect to come to work in US in Jan/Feb. 2012.
Now, ABF representative was assuring me that there will be no problems at the border/customs, and that I need just a form CBP 3299/declaration of unaccompanied articles (which is not a problem), and copy of Canadian passport. Will that copy of the passport be enough? The rep insists it's gonna be ok, but I am really worried that they will require the copy of L1 visa and that my shipment will get stuck at the border?
Anyone had same or similar move?
Please let me know because they are picking up the container on 23rd Nov!
Many thanks

Usually CBP does not permit unaccomapanied "pre-importation" of domestic goods until one has their I-94.

It has been the experiece of almost everyone I know that moves on TN, H1, L1, etc, that a copy of your valid I-94 (which is issued at time of person's entry into US on the approved status) is needed by the shipper to even approach the border.

The ABF person is correct that CBP 3299 is needed, but the CBP offcer will want to see the I-94 as proof that you are allowed to bring this stuff down duty free.

I'd be asking another ABF rep.

Right... so I've been researching online too and also found out that everyone recommends "entering first, and then your unaccompanied belongings".
How do you do this then? Where do you store your stuff in the meantime...? until you enter the US with work visa and get I-94?

Well, you get earliest approval for your status as possible, then go to the border to activate it, and then move.
That is just the way it is done.
Besides, until you get status, you have to keep Cdn residential ties anyways.

Ok, well, thanks, you certainly saved me some trouble here.
ABF listened to me this time, and they organized the container with belongings to be stored here in Brampton. Once I am in the US, with my status activated, I will provide them the copy of I-94, so they can ship it to the west coast. Easy-peasy. They are really being helpful with the whole organizing of the move.
Thanks again, and I'll certainly have lot more questions about the life over there!