[Xy-pic] rotate labels (follow-up)

[Wolfhart Totschnig]

Hi,

Let me follow up on the question I asked at the end of April. I can now 
further specify the problem I have. I hope someone will then be able to 
help me out.

I would like to rotate the labels in a diagram. I have the following:

\ar[ur]_{causation} \ar@{-}[u]_{predication} & ...

I would like to have both labels aligned with the arrows, that is, the 
one diagonally and the other vertically. With the Rotate and Scale 
extension, this should work by using the [@] modifier, if I understand 
correctly. So, with \xyoption{rotate} in the preamble, I tried:

\ar[ur]_[@]{causation} \ar@{-}[u]_[@]{predication} & ...

Yet this does not work. The labels are moved slightly (the first one up, 
the second to the right), but they are not rotated.
The Reference Manual says that, in order for the Rotate and Scale 
extension to work, there needs to be a suitable "back-end". But in my 
case, the back-end does not seem to be the problem. I found a 
work-around to rotate the labels, namely via the graphicx package and 
the \rotatebox command. This works, so my back-end can display rotated 
text. But with this work-around, I am only able to approximate what I 
have in mind, it doesn't give me exactly what I want (besides, it's 
rather clumsy), so I still would like to make the Rotate and Scale 
extension work. Is there anything else I need to load, besides the 
graphicx package, in order to make the extension work?

Thanks in advance for your help,
Wolfhart