Compiling trigger function with MinGW

Hello All.

Now I try to link dll with MinGW from Example in Postgres Help.
Linker show me this error:

D:\users\anthony\kursor\abzcrm\c\foo>gcc -shared foo.o -o foo.dll -L 
"d:/files/local/PostgreSQL/8.3/lib" -l postgres
Cannot export ⌂postgres_NULL_THUNK_DATA: symbol not found
collect2: ld returned 1 exit status

What should I do?

-- 
Anton Burkun
+380 66 757 70 27