I have been on H-1B visa for around 8 years(approved I-140) and am currently working in USA. My earlier stamped H-1B visa on passport expired in Sept 2010. My current I-797 is valid till April 2014.

My spouse(already on dependent visa from past few years) has gone on a visit to India. She will be going for her H-4 visa stamping in New Delhi Consulate. I would like to know if it is valid to apply for H-4 visa stamping based on Principal Applicant valid I-797, even when principal applicant's stamped visa on the passport has already expired. Will there be any issues and any precuation we need to take?