Blind attempt at fixing #23

src/win/patch.c

diff --git a/src/win/patch.c b/src/win/patch.c
index e7c30a6..737b0e2 100644
--- a/src/win/patch.c
+++ b/src/win/patch.c
@@ -99,7 +99,7 @@
 	static uint8_t pids[0x1000] = {0};
 	unsigned index = pid >> 2;
 	unsigned byte = (index >> 3) & 0xfff;
-	unsigned mask = index & 7;
+	unsigned mask = 1 << (index & 7);
 	int ret;
 	EnterCriticalSection(&s_cs);
 	ret = pids[byte] & mask;