Strange black sections on glass/liquid materials

Ok, I’m doing a render for a friend, but I’m getting a lot of weird looking black streaks in my materials, and I’m not sure what’s causing it.
Here is the render.
And here are the material settings for the glass, and the red liquid.(I think it’s something to do with the transparency settings, so that’s all I put in the screenshot)

Thanks for any help!

Set the raydepth higher (under the raymirror and raytransparent panels)
Raydepth can be a maximum value of 10, if it’s too low then you can get black.

That fixed it, thanks!

Good bye problems, helloooo render times!

Here’s the fixed up render, if anyone wanted to see it. I fixed a lot of other things as well. Now I just need to put it in a scene. D:

http://i14.photobucket.com/albums/a342/name_is_joseph/Tubesfixed2.jpg