WORKING FAMILY TAX CREDITS WHILST ON NEW SPOUSE VISA?

Hi

I was hoping someone could give me some advice and maybe reassurance.
I am English and my husband is Egyptian, 1 year ago he came here on the spouse visa under the new rules, I sponsored him on the agreement that I was earning £18600 per year, however I have now lost my job and am no longer earning but he is earning a full time wage although it is no where near £18600. We have a child also, I have put a joint claim in for working families tax credits and child tax credits and it has been approved. They have sent the back dated cheques all in my husbands name and I am just really confused as it is supposed to be a joint claim?

I know due to me being a citizen the claim will be treated as if we both are but will this damage our prospects for the next visa in a year and a half? by then I will be working and hopefully we wont need the tax credits by then but will it go against his next visa? and what happens if by then we are still receiving a little tax credits but earning jointly 18600? Can the fact that at this point in time we are not earning 18600 affect his current visa?

Sorry for all of the questions I am just a tad worried that after all of my hard work last year it could all be thrown away.

Anyone?

Claim child benefits in your name only and tax credits (working & child) must be claimed in both you and your spouse's names, this will not affect future visa applications.