According to "A Dictionary of Basic Japanese Grammar", ので cannot be used in sentences that contains a request in the main clause.
However, in many phrases at sites or another grammar books I have found cases like this:
ちょっと気分が悪いので、早く帰らせてください。
After that, I made a quick search on the Internet and noticed that the combination of " ~ので, ~てください" is not uncommon at all, although I have not reached at any conclusion about the reason. Is this gramitical rule simply ignored by most Japaneses, or there are special cases when the use of the pattern " ~ので, ~てください" is valid?
