I just tested it in Forge 1558 and I did not encounter any issue. Specifically, I was able to pick up a liquid in an iron bucket and place it again, then pick it up and place it once more. I also tested that the fluids did what they are supposed to (e.g. you can drown in water, lava hurts you and sets you on fire).
Are you using any other mods or can you reproduce this issue with just DeeperCaves installed?