IP Security - possible compromise

Question

I previously had an airport extreme and last October changed to AirPort Extreme (802.11n). WHile the security on the previous Airport extreme was set, I have concerns about my current one.
Recently I found some e-mails rejected by servers, that lead me to find my IP on 6 blacklists for spam; while I don't send any bulk mails. I have a feeling my IP has been compromised. Does anyone have any ideas how to increase security on my AirPort Extreme (802.11n) ?
Any ideas welcome
Thank you
Steven

Answer 1

I changed the setting to WPA2 Personal but now my computer can't find the Airport Express or my network.
The following are the minimum requirements for a wireless client to access a WPA2 encrypted network:
For a Mac:
o An AirPort Extreme Card
o OS X 10.3.3+
o AirPort for Mac 4.2
o AirPort Utility 5.0
For a PC:
o Windows XP w/SP2
o AirPort for Windows 4.2
o A wireless adapter that supports AES encryption.
Any idea how to get back to my own network by connecting to my Airport Express?
Try temporarily connecting directly to the base station using an Ethernet patch cable between the base station & your Mac.