I have a Mac Mini HTPC, core two duo with 2GB RAM in an upstairs bedroom. Using Home Sharing, we watch iTunes movies that are on a MacBook Pro, which is in a downstairs home office. Both computers are networked wirelessly with an Airport Extreme, and both seem to be running a 2.4Ghz wireless N signal. For some reason, starting the last couple of months, it takes the Mini forever to load a movie, and when it does, the movies sometimes freeze in the middle. I've done an internet speed test on the Mini, and it's getting about 15% of the full download speed, but 100% of the upload speed. Also, I've tested my iPad in the upstairs bedroom, and the movies load and run fine on it. So that tells me that the wireless signal should be fine on the second floor. Does it sound like the wireless card is bad on the Mini, and is there a diagnostic tool that I could use to let me know for sure? Should I look into getting a dual-band Airport Extreme, so I can run a dedicated 5Ghz signal (still need the 2.4Ghz signal for my wife's Dell laptop)? Any help is appreciated. This has stumped me for a while.