--- a/pe_profiling/operf.cpp
+++ b/pe_profiling/operf.cpp
@@ -857,11 +857,14 @@ static int __delete_old_previous_sample_
                                 int tflag  __attribute__((unused)),
                                 struct FTW *ftwbuf __attribute__((unused)))
 {
+	int err;
+
 	if (remove(fpath)) {
+		err = errno;
 		perror("sample data removal error");
-		return FTW_STOP;
+		return err;
 	} else {
-		return FTW_CONTINUE;
+		return 0;
 	}
 }
 
@@ -896,7 +899,7 @@ static void convert_sample_data(void)
 		return;
 
 	if (!operf_options::append) {
-                int flags = FTW_DEPTH | FTW_ACTIONRETVAL;
+                int flags = FTW_DEPTH;
 		errno = 0;
 		if (nftw(previous_sampledir.c_str(), __delete_old_previous_sample_data, 32, flags) !=0 &&
 				errno != ENOENT) {
--- a/libop/op_events.c
+++ b/libop/op_events.c
@@ -83,7 +83,7 @@ static int parse_hex(char const * str)
 static u64 parse_long_hex(char const * str)
 {
 	u64 value;
-	if (sscanf(str, "%Lx", &value) != 1)
+	if (sscanf(str, "0x%llx", &value) != 1)
 		parse_error("expected long hexadecimal value");
 
 	fflush(stderr);
