H1 amended

[mannshah24]

I am a contractor my employer applied H1B in 2013 when i was working with some ABC client and I got my H1B approved for 3 years and H1B going to start from 1st Oct 2013, then i got a new job with some other XYZ client in June 2013, so my employer updated my LCA with the new client and he said amended H1B may not be necessary, so from June 2013 (after updating the LCA) i am working with the XYZ client, Do i need to apply for amended H1B even after updating the LCA with the new location information ?
Employer is the same but client is different

Do you think it will be a problem... as my H1B was approved when i was with the client ABC and now i am working with the XYZ client...

Now i am planning to attend VISA interview in India so, before attending i need your valuable information and suggestion

Thanks in advance