Unfortunately this comes up with a lot of devices; especially when WPA is used :/ I usually recommend the following troubleshooting:
If your router supports any of the following, and you're willing to accept temporary security compromises please do each of the following:
- First make sure your router firmware is up to date. Often times there are release notes for more current versions that may address connectivity issues.
- Unplug the router from the internet if you are paranoid about turning off any of the following.
- Turn SSID broadcasting on.
- Turn off MAC address filtering.
- Turn off encryption <--- this is typically the source of the problem.
- Disable 802.11 mixed mode.
- Reboot router
- Then attempt to connect to router.
If you can connect successfully, you can begin modifying/increasing your security settings as desired.
If you determine the break point was encryption start by turning on WEP encryption which is the lowest level.
If WEP works and you want increased encryption/security, you can try WPA. If any of these breaks your ability to connect to your access point, please post in this thread.
Assuming your successful with encryption - you can turn each additional setting on - one by one - until something breaks.
If enabling one of these settings causes issues, please report your router model and the setting in this thread. It would also be helpful if you posted the same info if it does help.
If you are still having problems, after performing the above steps, please post the model # of your router and at least 30 minutes of log data from your access points log file. The log file can also be a good place to start as well.
Personally, I only turn on MAC address filtering and SSID broadcast. Being a security professional I understand this is not bullet proof. In fact if someone really wanted to sniff your traffic they could. On the other hand, I'm not the most interesting person in the world and I'm not that concerned about it. I live in an environment that doesn't really lend itself for needing a very strong level of security. My primary goal is to prevent piggy backing off my network to get free service. The two things above have effectively prevented that.
Edited: Added some more to the above so read again if you read it already in the last 10 minutes. I left out a bunch of stuff.