diff --git a/src/libopensc/reader-pcsc.c b/src/libopensc/reader-pcsc.c
index 96ce8ee2..63f388a4 100644
--- a/src/libopensc/reader-pcsc.c
+++ b/src/libopensc/reader-pcsc.c
@@ -234,41 +234,47 @@ static int refresh_slot_attributes(struct sc_reader *reader, struct sc_slot_info
 	}
 	if (pslot->readerState.dwEventState & SCARD_STATE_PRESENT) {
 		int old_flags = slot->flags;
+		int maybe_changed = 0;
 
 		slot->flags |= SC_SLOT_CARD_PRESENT;
 		slot->atr_len = pslot->readerState.cbAtr;
 		if (slot->atr_len > SC_MAX_ATR_SIZE)
 			slot->atr_len = SC_MAX_ATR_SIZE;
 		memcpy(slot->atr, pslot->readerState.rgbAtr, slot->atr_len);
+
 #ifndef _WIN32
-		/* If there was a card in the slot previously, and the
-		 * PCSC driver reports a state change, we assume the
-		 * user removed the old card and inserted a new one in the
-		 * meantime. */
-		if ((pslot->readerState.dwEventState & SCARD_STATE_CHANGED)
-		 && (old_flags & SC_SLOT_CARD_PRESENT))
-			slot->flags |= SC_SLOT_CARD_CHANGED;
+		/* On Linux, SCARD_STATE_CHANGED always means there was an
+		 * insert or removal. But we may miss events that way. */ 
+		if (pslot->readerState.dwEventState & SCARD_STATE_CHANGED) {
+			slot->flags |= SC_SLOT_CARD_CHANGED; 
+		} else { 
+			maybe_changed = 1; 
+		} 
 #else
-/* The above doesn't work on Win32 because there are other events,
- * so this code will set the SC_SLOT_CARD_CHANGED most of the time,
- * resulting in a complete re-read of the card.
- * So we give the card handle to a function (SCardStatus) and see
- * if it returns SCARD_W_REMOVED_CARD.
- */
-		if ((pslot->readerState.dwEventState & SCARD_STATE_CHANGED)
-			 	&& (old_flags & SC_SLOT_CARD_PRESENT)) {
+		/* On windows, SCARD_STATE_CHANGED is turned on by lots of 
+		 * other events, so it gives us a lot of false positives. 
+		 * But if it's off, there really no change */ 
+		if (pslot->readerState.dwEventState & SCARD_STATE_CHANGED) { 
+			maybe_changed = 1; 
+		} 
+#endif
+		/* If we aren't sure if the card state changed, check if 
+		 * the card handle is still valid. If the card changed, 
+		 * the handle will be invalid. */
+
+		if (maybe_changed && (old_flags & SC_SLOT_CARD_PRESENT)) {
 			DWORD readers_len = 0, state, prot, atr_len = 32;
-			byte atr[32];
+			unsigned char atr[32];
 			int rv = SCardStatus(pslot->pcsc_card, NULL, &readers_len,
 				&state,	&prot, atr, &atr_len);
 			if (rv == SCARD_W_REMOVED_CARD)
 				slot->flags |= SC_SLOT_CARD_CHANGED;
+			else
+				slot->flags &= ~SC_SLOT_CARD_CHANGED;
 		}
-#endif
 	} else {
 		slot->flags &= ~(SC_SLOT_CARD_PRESENT|SC_SLOT_CARD_CHANGED);
 	}
-
 	return 0;
 }