Due to interaction between the MSL C library and the GUSI I/O library I can get reads from sockets to work consistently either for unbuffered binary files or for buffered binary files, but not for both:-(

The workaround is to force socket.makefile() to disable buffering for binary files.

Fixes bug 534625. 2.2.1 candidate.
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index ef5967a..4f35b32 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -1365,6 +1365,11 @@
 			SOCKETCLOSE(fd);
 		return s->errorhandler();
 	}
+#ifdef USE_GUSI2
+	/* Workaround for bug in Metrowerks MSL vs. GUSI I/O library */
+	if (strchr(mode, 'b') != NULL )
+		bufsize = 0;
+#endif
 	f = PyFile_FromFile(fp, "<socket>", mode, fclose);
 	if (f != NULL)
 		PyFile_SetBufSize(f, bufsize);