[Build Craft crashes with Mac? Please Help fast]

Ok, i will make a bug report, because i dont think many people have the exact same client problem. Thanks for your advice, hopefully there is a fix!

[Build Craft crashes with Mac? Please Help fast]

Me and a friend of mine (who is using a mac) was playing on a server. we got to a point where we could afford to make a quarry. I started to make steam engines and the quarry. when we were ready i flipped the levers to the steam engines and suddenly he crashes. The server and I was all good, but my mac friend just crashed.

I thought i would start putting some conductive pipes down, but whenever i place a conductive pipe down he crashes. i start looking at Google for answers, and i found one where you have to delete the Buildcraft folder in the rail craft folder in the server files. I asked the owner of the server, and he deleted the Buildcraft folder, but my friend still crashes.

Is there a fix or a thread i missed that fixes this problem?

please help