From my experience with 203k loans, the best advice is to use a lender that offers assistance via third party with 203k processing.
This shortens the closing time by weeks. Try http://www.cfs-mortgage.com/203k for more information.
The best way to find that answer is to ask the question to the lender handling the transaction directly.
There could be any number hurdles to meet.
One current delay I have seen is that the borrower's 4506T (transcripts from the IRS).
Also, if gift funds are being used and were not documented correctly, lender may be waiting for new bank statements to come out.
And the possibitlites are endless and always surprising!
Regardless of the delay, I would encourage you to have your agent speak directly with the loan agent handling the transaction.
Missing a deadline by a day or two is frustrating enough. 30 days? Yikes. The loan officer should be more than willing to explain to everyone in detail what the hang up is in this transaction.
Communication is the key to not only success but in keeping all parties calm and cool.
I would ask your agent to speak with the buyer's loan agent directly.
I know it is frustrating. You deserve to know what is going on...