problem calling API when loading dynamically

Hello,

I've got a weird problem in that I'm unable to call the
"GetDefaultUserProfileDirectory" API when I dynamically load it however it
works fine if I explicitly reference it. (I've probably got the terminology
wrong but I'm sure you will see what I mean)

If I use the call "_GetDefaultUserProfileDirectory" below I get an Access
Violation error, if I use GetDefaultUserProfileDirectoryA all functions as
expected. I don't understand why one would work while the other doesn't when
they are both the same.

Thanks in advance,
David


function GetDefaultUserProfileDirectoryA (lpProfileDir : PChar; var
lpcchSize : dword) : BOOL;stdcall;far; external 'userenv.dll';

function GetDefaultUserProfileDirectory:string;
  type
    Type_GetDefaultUserProfileDirectory = function(lpProfileDir:PChar;var
lpcchSize:DWORD):Boolean; StdCall;
  var
    len : DWORD;
    iResultCode : integer;
    _GetDefaultUserProfileDirectory   : Type_GetDefaultUserProfileDirectory;
    sProfilePath: string;
    bResult: boolean;
  begin
    len:=65536;
    SetLength(sProfilePath, len);
    iResultCode:=LoadLibrary('userenv.dll');
    @_GetDefaultUserProfileDirectory:=GetProcAddress(iResultCode,'GetDefaultUserProfileDirectory');
    //bResult:=_GetDefaultUserProfileDirectory(PChar (sProfilePath), len);
    bResult:=GetDefaultUserProfileDirectoryA(PChar (sProfilePath), len);
    result:=PChar(sProfilePath);
    FreeLibrary(iResultCode);
end;