Hello, Horsenut101.
Thank you for using Apple Support Communities.
Sometimes a simple power cycle of the router can correct the issue that you are experiencing. However, the issue could be a little more complex. Wi-Fi routers need adjustments to settings periodically for optimized performance with the constant progression of wireless device technology. Below, I have included two articles. The first article will cover basic Wi-Fi troubleshooting. The second article cover the recommended settings for current Wi-Fi access points.
Troubleshooting Wi-Fi issues in OS X Lion and Mac OS X v10.6
http://support.apple.com/kb/HT4628
iOS and OS X: Recommended settings for Wi-Fi routers and access points
http://support.apple.com/kb/HT4199
Cheers,
Jason H.