Hi Mandi, to repeat from your other post on this topic, a 2008 era machine may have a battery that is sufficiently degraded that it can not power the system and the transmitters when low.
What does it say about the battery in: apple menu, About This Mac, More Info, System Report, Hardware, Power about battery Condition, Capacity, Cyles and Voltage? The Bluetooth and WiFi tranmitters may be asking for too much power so the system controller may be cutting back on them to protect the more critical parts of the system.
You could also visit an Apple genius bar and have them run some diagnostics to more fully test the strength of the battery.