How to add Asus connected printer to 2nd PC

[Old Harry]

Installing Canon iP4000 to router from first PC works fine (Windows XP, LPR,LPRServer, 9100 becomes 515, USB, firmware 1.8.1.9). After installing in the same way on 2nd PC printing test page is not possible and also printing on first PC is no longer possible. I tried also to add the printer as a network printer, but then it cannot be found! Should the printer be set to shared? Any suggestions?

[Styno]

Have you disabled Windows XP firewall?

[Old Harry]

Sure, but ZoneAlarm is running.

[Styno]

Well, disable it and try again...

[Old Harry]

I closed ZoneAlarm, but no improvement. Moreover, the wireless connection is a 'trusted zone' and Spooler Subsystem App is an allowed application for ZoneAlarm. These settings do prohibit Zonealarm to intervene; isn't it ?