Currently Being ModeratedSep 19, 2013 3:48 PM (in response to VLanc)
Are you using a 802.11n (any generation) AirPort Extreme with an attached USB HDD for Time Machine backups? If so this configuration is NOT supported by Apple and most people who post here have experienced data loss or corruption doing so.
Currently Being ModeratedSep 19, 2013 4:01 PM (in response to Tesserax)
I believe the Airport is 802.11n. Airport Utility is showing radio mode as 802.11a/n 802.11b/g/n (Automatic). I'm not sure what you mean about a USB HDD. The Airport and Time Machine are one unit and connected wirelessly. It has worked with this configuration for a long time. I'm not sure if it is relevant but Apple replaced my hard drive in May as part of the Hard drive replacement program.
Currently Being ModeratedSep 19, 2013 4:13 PM (in response to VLanc)
HDD = Hard Disk Drive.
I just wanted to make sure what you have. If I understand you correctly you then have a Time Capsule; an AirPort Extreme with a built-in HDD. If this is correct, then of course, it support Time Machine as a backup destination.
I am not aware of any current software issues for Time Machine; however, anything is possible.
At this point I would recommend that you check out Apple Support Communities Time Machine expert Pondini to go through some of his troubleshooting techniques.