Furry stuff, oekaki stuff, and other stuff.
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Open the layers box first thing.
If you do that it will work fine.
It took me awhile to figure that out.
If that doesn't work, then idk.
Wacintaki 1.2.5 was when ShiPainter was updated to version 1.114. It's possible that the previous version of the applet doesn't have this problem.
To try this, go into the Wacintaki archive and download version 1.2.4. Then, copy the "spainter_all.jar" file to your server. If the older version has the same problem, it's a good idea to copy the newer version back, because one older version of ShiPainter had a tendency to corrupt animation files (I forget which one, though).
This is kind of a minor issue, but it can be annoying and I thought I'd bring it up in case it wasn't known.
While it seems to work properly in an older version of wacintaki that a friend has (1.2.4, heh), in newer wacintakis the color picker (the one listed under the eraser, not the slider stuff at the bottom; that works fine) doesn't seem to pick up right clicked colours in ShiPainter. It just stays at whatever it was when you opened it.