spicey dear, what do you mean by tenth birthday certificate.
anyways, if you meant by school leaving certificate, i think that might suffice along with a affidavit and expalnation letter.
to the best of my knowledge, upto september 2010 CIC considered School LC as proof of birth, but after that it has made it compulsory. if you check the excel link i had posted, all the case of rejection due to non availability of birth certificate are from India (New Delhi V/O).
Dont take me negatively but i just want you all to ensure that you try your best to enclose your birth certificate. i dont want anyone's application coming back (including mine ... lol).
Nish