  At finite temperature a breakdown of the hard thermal loop expansion arises
whenever external momenta are light-like or tend to very soft scales. A
resummation of ladder graphs is important in these cases where the effects of
infrared or light-cone singularities are enhanced. We show that in hot QED
another class of diagrams is also relevant at leading order due to long range
magnetic interactions and therefore recent studies about ladder expansions need
to be corrected. A general cancellation of the hard modes damping effects still
occurs near the light-cone or in the infrared region. The validity of an
improved version of the hard thermal loop resummation scheme is discussed.
