Re the folder permission problem:
The mambot stores (caches) some retrieved data in the /cache/ folder which should be writeable anyway - yours appears not to be.
Regarding the character set problem:
The better / preferred solution:
http://www.deanmarshall.co.uk/demo/apf_bridge/component/option,com_fireboard/Itemid,57/func,view/
id,195/catid,2/A second - more drastic - and more experimental - solution:
http://www.deanmarshall.co.uk/demo/apf_bridge/component/option,com_fireboard/Itemid,57/func,view/
id,222/catid,2/Hope that helps.
Dean