playBunny and Nabla: thanks!
from experience i already dont worry that much about a hole on 3 .. i dont like holes on 2 though .. but i now understand that a hole on 4 (or 5) is even worse :)

another nice example which was posted yesterday on dailygammon is the position discussed in this thread :
http://www.dailygammon.com/bg/forum2/main/read/22269#19