Lost Passport - US Visitor Visa

[canvis2004]

Hi everyone,

I am on work permit in Canada.
I have applied for US visitor visa (b1/b2) 2 times, in 2000 and in 2003 and both times the Visit Visa was issued(from american embassy, switzerland).
The 2nd time they took 9 months to process it and get approval from washington and gave me a 5-year visa.

Unfortunately I lost my passport..........

When i applied last year with new passport (just 2 months into my IT related job), the officer refused it saying that i am not "established" enough in my job. He had no other reason to refuse. He even interviewed me about IT stuff related to my job....

I would like to know if I should apply now that its been more than 1 year in the same employment. The only reason to want the US visa is so that i can travel to Buffalo in case i am invited by Canadian consulate Buffalo for immigration interview.

Is 1+ year of employment enough to prove establishment in job?

I am just wary of the 2 previous refusal stamps in it.
I do have a valid multiple entry "worker" visa for Canada in my passport.

Should I get an invitation? Where can i find sample of invitation letter?

I hope somebody can offer me advice on this important matter.

Thanks.