Melting ores bug?

[Qeewee]

I try melting blue ores and coal, it says I start to melt them, but then I can just walk away without a new message saying I interrupt my work, the furnace is still lighted and I have to wait several minutes for it to be able to use again.. Anyone know what the problem is?

[Atulos]

You need pure fires to smelt merinium.

[Llama]

Leaving the furnace lit is a bug - please report it to mantis

http://illarion.org/mantis/

Thank you.