They need to be pretty speedy because the original filing deadline for 1099s was 1/31. There at least used to be a $15 fee for each corrected 1099 was $15 if they were filed within 30 days, $30 if filed after 30 days but before 8/1 and $50 thereafter. So the corrected form needs to be out to you by March 1 to avoid the higher penalties.
The cost of corrections is why I will question a 1099 that does not reconcile to my records but as long is it is not drastically overstating my income I won't bother to demand a correction. I generally make my 1099 inquiries by email so I can print the 'explanation' email response to file in the folder with my copy of my tax return for the year. So one US based company for whom I earned more than $1000 in fees who told me they 'don't send 1099s' the money will be claimed on my return and the email correspondence will become part of my permanent tax file. Another who explained in their email that the fees to get payment to me constituted 'income' to me is also being printed to drop in my file. One that explained that reimbursements are 'income' to me is also being printed and dropped in the file. All three of these are dead wrong but 'our accountant told us to do it that way'. Ok. At least I have my backup that I attempted to contact them and what their response was.