Index: src_plugins/hid_gtk/gui-output-events.c
===================================================================
--- src_plugins/hid_gtk/gui-output-events.c	(revision 1532)
+++ src_plugins/hid_gtk/gui-output-events.c	(revision 1533)
@@ -173,9 +173,12 @@
 		if (state & GDK_MOD1_MASK)    mods |= M_Alt;
 		if (state & GDK_CONTROL_MASK) mods |= M_Ctrl;
 		if (state & GDK_SHIFT_MASK) {
-			mods |= M_Shift;
-			if ((kv >= 'A') && (kv <= 'Z'))
-				kv = tolower(kv);
+			static const char *ignore_shift = "~!@#$%^&*()_+{}|:\"<>?";
+			if ((kv > 32) || (kv < 126) || (strchr(ignore_shift, kv) == NULL)) {
+				mods |= M_Shift;
+				if ((kv >= 'A') && (kv <= 'Z'))
+					kv = tolower(kv);
+			}
 		}
 
 		slen = hid_cfg_keys_input(&ghid_keymap, mods, kv, seq, &seq_len);