MC 1.7.10
Forge 1208
TSteelworks-1.7.10-1.0.5
TConstruct-1.7.10-1.7.0d3.1

When using a high oven, once a single type of metal smelts and enters the high oven's liquid inventory, it will cease to accept any other kind of molten metal until all of that type is removed.

I.E. when smelting Iron, Copper, Gold, Tin, Aluminium, and Silver, the tin will smelt first, and then the progress bars will stay maxxed out on all others but only Tin will be accepted.

Intended, as stated in Steelworking and you since 1.6. It was actually bugued in 1.6 and fixed for 1.7. You can move your liquids to a deep tank and process them there though.

You can also still have steam & water in the same high oven