UPDATE: The problem exists in r8169 module. After removing it then downloading from Realtek homepage and installing r8168 driver (version r8168-8.027.00) the problem disappears.
NOTE: r8168-8.027.00 is not correct, it can be installed after you patched it. Please check the following page for that: http://code.google.com/p/r8168/issues/detail?id=8
UPDATE: The problem exists in r8169 module. After removing it then downloading from Realtek homepage and installing r8168 driver (version r8168-8.027.00) the problem disappears.
NOTE: r8168-8.027.00 is not correct, it can be installed after you patched it. Please check the following page for that: http:// code.google. com/p/r8168/ issues/ detail? id=8