Techie is right. There are some other forums regarding to this subject:
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1729;start=msg11101#msg11101
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1696;start=msg10688#msg10688
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1677;start=msg10606#msg10606
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1664;start=msg10456#msg10456
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1611;start=msg10408#msg10408
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1651;start=msg10313#msg10313
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1561;start=msg9590#msg9590
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1479;start=msg8916#msg8916
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1386;start=msg7917#msg7917

To configure avast4.ini file, see http://www.avast.com/forum/index.php?board=2;action=display;threadid=1647;start=msg10270#msg10270