more Windows XP build problems
```
  building 'pandas._sandbox' extension
  C:\Program Files\Microsoft Visual Studio 9.0\VC\BIN\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:C:\Python26\libs /LIBPATH:C:\Python26\PCbuild /EXPORT:init_sa
  ndbox build\temp.win32-2.6\Release\pandas\src\sandbox.obj /OUT:build\lib.win32-2.6\pandas\_sandbox.pyd /IMPLIB:build\temp.win32-2.6\Release\pandas\src\_sandbox.
  lib /MANIFESTFILE:build\temp.win32-2.6\Release\pandas\src\_sandbox.pyd.manifest Creating library build\temp.win32-2.6\Release\pandas\src\_sandbox.lib and obj
  ect build\temp.win32-2.6\Release\pandas\src\_sandbox.exp
  sandbox.obj : error LNK2019: unresolved external symbol _get_base_ndarray referenced in function ___pyx_pf_6pandas_8_sandbox_9foo3
  build\lib.win32-2.6\pandas\_sandbox.pyd : fatal error LNK1120: 1 unresolved externals
  error: command '"C:\Program Files\Microsoft Visual Studio 9.0\VC\BIN\link.exe"'
  failed with exit status 1120
```
