+<li><p>Finally, if you have installed TinyOS 2.0.1, there is a bug in TOSSIM (which will be fixed in 2.0.2).
+The bug is in file <tt>tos/chips/atm128/sim/atm128_sim.h</tt>. Change these lines 22 and 23 from:
+
+<pre>
+#define _SFR_IO8(io_addr) _MMIO_BYTE((io_addr) + 0x20)
+#define _SFR_IO16(io_addr) _MMIO_WORD((io_addr) + 0x20)
+</pre>
+
+to
+
+<pre>
+#define _SFR_IO8(io_addr) _MMIO_BYTE((io_addr))
+#define _SFR_IO16(io_addr) _MMIO_WORD((io_addr))
+</pre>
+
+If you do not do this, then timers will not work correctly.