### plot3d not displaying - only says "Graphics3d Object"?!

Hello

I have a problem, I hope you can help. I'm trying to use plot3d, but instead of drawing a plot, it just prints out the text "Graphics3d Object"

Here is an example Sage snippet that exhibits this problem:

```
f(x,y) = abs(x*y)
X = plot3d(f, (x,105,72), (y,0.8293,55.8271));
show(X)
```

I have seen some functions plot OK -- I can't see a pattern to when it does and doesn't work. For example, this does work:

```
f(x,y) = abs(x*y)
X = plot3d(f, (x,0,10), (y,0,10));
show(X)
```

This bug is repeatable. I am using 64 bit Linux Mint (Ubuntu), and using the notebook in latest Firefox.

Any help much appreciated.
Thank you,
- Daniel