In submitting an I-130 application for my mother to immigrate to the USA, the INS sent back to me a request for a better copy of my birth certificate. I had a certified copy from the Philippines sent to me which I can give to the INS. However, the date of birth on the certificate is one day different then my real birthday. I don't know why this happened, but I am worried this may be a problem when I resubmit the certificate to the INS. I will write a letter of explanation saying they misprinted the 16th when it should have been the 15th. Do you think the INS will have a problem with this? My I-130 application, naturalization form, and other i.d. all say the 15th which is the correct day, but this new certificate I just got form Manila says the 16th. Please give me your advice, Thanks.

The different dates of birth could indeed create confusion for the USCIS.
Is it possible to get a birth certificate from the Philippines with your correct date of birth, or at least a letter from the appropriate Filipino official explaining that your date of birth is the 15th?
If not, then you should submit an affidavit explaining the mistake.