Access Violation while using mpz_init function

[Idler Fang]

I've compiled gmp 4.0.1 under MinGW with "--disable-static --enable-shared". 
Then I get a dll file and a def file. I use LIB /MACHINE:IX86 
/DEF:libgmp-3.dll.def to generate a LIB file for Microsft Visual C++. Then I 
created a Win32 Console project and imported libgmp-3.lib. The link was OK but 
an access violation error occurs when I call mpz_init function. I don't know 
what about the other functions, as it is the first function to call. I tried 
again under Cygwin and the same error occured.
Did I make any mistake on compiling?
Looking forward to your help. Thanks.