The class name needs to be converted to a getptr.
diff --git a/windows/class.c b/windows/class.c
index 362ce25..c2b94f7 100644
--- a/windows/class.c
+++ b/windows/class.c
@@ -1068,6 +1068,8 @@
wc->hCursor = classPtr->hCursor;
wc->hbrBackground = classPtr->hbrBackground;
wc->lpszClassName = (SEGPTR)CLASS_GetClassNameA( classPtr );;
+ if (HIWORD(wc->lpszClassName)) /* Make it a SEGPTR */
+ wc->lpszClassName = SEGPTR_GET( (LPSTR)wc->lpszClassName );
wc->lpszMenuName = (SEGPTR)CLASS_GetMenuNameA( classPtr );
if (HIWORD(wc->lpszMenuName)) /* Make it a SEGPTR */
wc->lpszMenuName = SEGPTR_GET( (LPSTR)wc->lpszMenuName );