COS from B2 to F1 ..Received Blue letter

[Amit2009]

Hi
I came to US on sept 09 on b2 visa...dec 09 I applied for change of status..
to F1..after I got I20 ..I have just received a blue letter asking for more financial document to prove that i can take care of my tution fees..
My Sponser is my mother who is on H1b visa..and we have already given them bank letter ....now california center wants bank statement..
and other financial documents...
Can any body tell me why they have asked this??
Has anybody got this kind of letter??
Has anybody F1 visa been approved after the blue letter recently since heared lot of negative things??

thank you in advance

[kabkaba]

You need enough funds for 1 year in savings/checking/CD accounts and funds for rest of the years in other types of accounts (non-liquid). They may have missed the bank statements, send it again. Expenses are shown on your I-20.

[Amit2009]

Thanks...
But the thing is..my mom just transferred lot of amount back home...for grandmother..i hope they dont see this as a fruad..as we dont have that much money left in bank account that we showed in bank letter..
Though now i will be sending them my back home property and bank statement..which is more than the expenses i need to show...
will this help...