I'm not sure about the 105's (I don't remember any speakers, but I didn't look very hard), however I've fixed a number of 100/200's iirc. There are two problems, firstly : the unit itself is pretty much OEM reject quality, they produce a lot of heat and have a extremely noisy radio. Telkom got these for next to nothing, slapped on a new enclosure and hacked the firmware a bit. Anyway, some of the units have tiny little 2cm odd fans, these are extremely whiny and die very easily. If its whining, it'll be dead soon, once it dies, the unit will soon cook itself. The first unit I saw had melted the top surface, caving in and creating a fire hazard

If you cant bin the router, I'd suggest cutting a large hole out of the upper surface and perhaps putting in a low rpm 8cm fan (4cm is fine, but they're noisy and unreliable... and you can get 8cm at any PC store).
The next thing is, the firmware is terrible: It's a very hacked together combination, rebranded and with a few changes to default values. That said, the source is _ancient_ (you can find it if you dig around, but the kernel is from ~2003), there's a lot of stuff that's not really working, unsafe fixes and bandages. The people who rebranded it and made the required changes seemed to even be struggling to compile it. That said, the WPA key issue was pretty simple; the PSK can not contain non-hex characters - like a WEP key. I have a feeling the hardware could just do WPA/2, and the guys that hacked the firmware for Telkom were tasked with adding support for it, however they didn't change the checks to allow the correct characters. I think it also has the same character limit.
Try making your pass out of [0123456789abcdef] - DEADBEEF or whatevs.
YMMV