I just updated my little private server to 1.6.4 including galacticraft, buildcraft, and chickenchunks mods. When I run a single player game I have oil and can edit proclivity such that there is a butt load, yet if I then make that world my server world, the blocks are empty where oil should be, resulting in weird shapes in water where geysers should be for example.

If there is a fix for this I would really like to know. Thanks.

I would first have checked that there is nothing wrong with the configuration file for BuildCraft and that the file on the server and the client are identical. The server will normally delete blocks from the world during loading if the block id is unknown.

If you find inconsistencies you could simply delete them and let the server generate a brand new file and then copy that to the client.

Sounds like a config issue.

This was not a bug. Forge now has two server jars and I was using the vanilla one. sorry.