Hi,
I am an International student (from India) came to USA to do my MS. I worked for a company on CPT and OPT in 2009. I want to file my taxes this year. The question is.. I am getting more refunds if I do 1040 instead of 1040nr. Please tell me if it will a problem if I fill 1040 instead of 1040nr. Thank you.

If you did not complete 5 years on F-1/OPT you must file nonresident tax return with Form 8843.
Since you are from India, as per tax treaty, you can claim standard deduction instead of itemized deduction. So it should not make any difference in tax if you file Form 1040 or Form 1040NR. Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents

Thank you so much for your reply. I have sent you an email regarding my tax returns to [email protected]. Please reply when possible.
Thanks again.