Luddite said:
The rules simply say it affects a 30 degree cone, so i see no issue with using it in melee. Exhibit A; http://2.bp.blogspot.com/_DywR7I8nHZ4/SwHFb_KfYxI/AAAAAAAAAGE/bjSB1D6SKRE/s1600/CodexWitchHunters.jpg (the cover of the Witch Hunters Codex). That flamer shot is definately at less than 3 meters so counts as in melee (or point blank - the DH rules are not clear, but 3m or less appears to be either point blank or melee depending on whether one or both opponents declared a melee attack). Looks possible to me (within the construct of 40k, and as clear by the rules of DH).
Art shmart. Art also says that Space Marines have tiny tiny heads. And I think that's some artist's idea of an Inferno Pistol (which logically should suffer from similar issues as do flamers, but let's not go there), even though it actually looks like a laser-as-seen-in-science-fiction-movies.
It certainly isn't firing in an area of effect cone.