Urgent, Xiaobaitu please!

Can I work for new employer before I get receipt for H-1 transfer? The new boss asks me to start work right after they file H-1 transfer for me.

One more question: my H-1 will be 6-year by sep.2008. Right now the new employer will do 2-year H-1 for me. So it will end by May 2009. My NIW I-140 has beed approved but not file I-1485 yet. Is there any problem to ask H-1 beyond 6-year?

Thanks!