Index: src/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c
===================================================================
--- src/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c	(revision 26114)
+++ src/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c	(working copy)
@@ -80,8 +80,11 @@
     int  repeat = 1; /* assume repeat */
     long time = TIMER2_VALUE + current_tick*TIMER_TICK; /* to timer unit */
     long v = (time - last_wheel_post);
-    if (v < WHEEL_LOOP_INTERVAL) /* avoid too frequent updates */
+    if (v < WHEEL_LOOP_INTERVAL) { /* avoid too frequent updates */
+        if(v < 0)
+            last_wheel_post = time;
         return ;
+    }
 
    /* interpolate velocity in timer_freq/timer_unit == 1/s */
     if (v) v = TIMER_FREQ / v;