Problem may be with the DSL modem firewall, if
used in addition to
a wireless router. You may have to create a rule to deny incoming ping requests in the modem. That is what I did to resolve this problem, if it really is a problem. Tinkered with ZA and Linksys setup first without success, then tried the modem. Don't just set the modem firewall setting to 'high' or 'off' (default 'low'), use 'custom' and create a specific rule. Use p/w 'admin' to access the management interface. You may also need at least a temporay hardwired connection to do this.

Operating System:Windows Vista Ultimate
Software Version:7.1 (Vista)
Product Name:ZoneAlarm Internet Security Suite