H1B petition was approved in April 08 and valid since Oct 08. I didn’t do COS within US and haven’t stamped H1B to my passport yet, since my F1 status is still valid--F1 stamp is valid till 2011, EAD is valid till August 12 09 and I have a new signature from my school on I-20. Also I-94 says I’m F1.

I have traveled outside of US between April and now and entered in F1/OPT at least 3 times. I would like to travel again in July and enter in F1/OPT. My company is concerned about this travel, but they don’t tell me why. Do you think I could have problems when I am entering US after 1 week of vacation? Will immigration officer at the border have the information about my approved H1B? If so is this a problem?
I have an appointment in my home county in Europe to stamp H1B in early August.