'Dedicated / Devoted'

A question from Ikram in Pakistan:

I really appreciate your efforts to help us to learn and improve English language. I have a query about two words in English language. 'dedicated' and 'devoted' are the two words which are commonly used in speaking and writing. I am well aware of the meanings of the two words.

My question is that in some situations we prefer to use the word 'dedicated' rather than 'devoted' while in other circumstances we prefer to use 'devoted'.

Please enlighten me when it is appropriate to use 'dedicated' rather than 'devoted' and vice versa.

Thanks in advance.
Regards Ikram-ul-haq

Listen to the answer on http://www.bbc.co.uk/worldservice/learningenglish/radio/specials/1837_aae/page14.shtml