Todd has been having a lot of problems getting his 2009 iMac to boot with Mavericks, and he's been having problems with audio cutting out when watching videos. Leo says that Mavericks seems to have a lot of bugs, and since most of them are not consistent on every machine, it's hard for Apple to fix them. We put Apple up on a pedestal, and expect more from them, but there are bugs and problems nonetheless. Leo says that his installation sounds particularly bad, so he should try reinstalling Mavericks. If the problem persists, it could be that he has a failing hard drive. The chat room says that many 2009 iMacs have defective hard drives, so that could be the issue.
With iOS 7, he's been having trouble with Wi-Fi on his iPad. Leo says it's a known issue. There's still no fix, and Apple hasn't been willing to replace his device for him. Unfortunately, he may just be out of luck at this point since it's likely a hardware issue.