Victor: I am in the midst of my second stint as a consultant (first time was 94-96), and in my opinion, you were not being too harsh. This is not even a programmer issue -- it is a business issue (as you recognize). In fact, I think the issue at hand has little to do with the invoicing scenario you mention. At the bottom is this fact: he informed you that he was out of money but asked you to keep working anyway. You said "no" unles he proved that he could, in fact, pay you for services rendered... by doing so! This is not unreasonable.

And as for his arrogant and condescending advice to you, I think he's dead wrong. Business is ALL about demands. Demands on time, demands on performance, demands on rates. We're not doing this to be liked, we're doing it to make money. (Other reasons, too, but you get my point I hope). Welcome to capitalism, Mr. Client. And please don't take my desire to actually get paid so personally!!

[This reminds me of a situation I had several months ago, when a potential client said she might or might not contract me... I sent an email a week later saying that I was about to sign on for some other work that would not allow me the time to work on her contract, so I needed an answer within a few business days. Her one sentence response, and I quote: "do you make a habit out of pressuring people like this?" I responded nicely and professionally, informing her that I was trying to give her "first dibs" on my time, which was more than I had any obligation to do! But then, of course, I did not repeat my offer to her, and I took the other job.]