diff -ur gaim-1.0.0/src/protocols/oscar/oscar.c gaim-1.0.0mx/src/protocols/oscar/oscar.c
--- gaim-1.0.0/src/protocols/oscar/oscar.c	2004-09-08 04:49:08.000000000 +0300
+++ gaim-1.0.0mx/src/protocols/oscar/oscar.c	2004-09-19 12:26:50.000000000 +0300
@@ -56,7 +56,7 @@
 #define AIMHASHDATA "http://gaim.sourceforge.net/aim_data.php3"
 
 #define OSCAR_CONNECT_STEPS 6
-#define OSCAR_DEFAULT_CUSTOM_ENCODING "ISO-8859-1"
+#define OSCAR_DEFAULT_CUSTOM_ENCODING "CP1251"
 
 static GaimPlugin *my_protocol = NULL;
 
@@ -417,7 +417,7 @@
 	if ((charsetstr == NULL) || (*charsetstr == '\0'))
 		return NULL;
 
-	if (strcasecmp("UTF-8", charsetstr)) {
+	if ( (isUTF8(data,datalen)==0) &&  strcasecmp("UTF-8", charsetstr)) {
 		if (fallback)
 			ret = g_convert_with_fallback(data, datalen, "UTF-8", charsetstr, "?", NULL, NULL, &err);
 		else
@@ -559,6 +559,49 @@
 	return;
 }
 
+
+int isUTF8(char *str, size_t len)
+{
+	size_t i=0,tomatch;
+
+	while (i<len)
+	{
+		tomatch=-2;
+		/* If starts with bit 0 */
+		if ((str[i]&0x80)==0x0) tomatch=0;
+		else
+      		/* if starts with 110, and next starts with 10 */
+       		if ((str[i]&0xe0)==0xc0) tomatch=1;
+       		else
+   		/* if starts with 1110 and next two start with 10 */
+      	        if ((str[i]&0xf0)==0xe0) tomatch=2;
+	       	else
+	        /* if starts with 11110.and next 3 start with 10 */
+		if ((str[i]&0xf8)==0xf0) tomatch=3;
+		else
+		/* if starts with 111110.and next 4 start with 10 */
+		if ((str[i]&0xfc)==0xf8) tomatch=4;
+		else
+		/* if starts with 1111110.and variable numer of next chars starts with 10 */
+		if ((str[i]&0xfe)==0xfc) tomatch=-1;
+
+		if (tomatch==-2) return 0;
+		if (tomatch==-1)
+			while ( (str[++i]&0xc0)==0x80 && (i<len) ) continue;
+		else
+			while (tomatch!=0 && i<len)
+			{
+				if ((str[++i]&0xc0)!=0x80) return 0;
+				tomatch--;
+			}
+		i++;
+	}
+
+	return 1;
+
+
+}
+
 gchar *oscar_caps_to_string(guint caps)
 {
 	GString *str;