I've just installed Mint 8 Xfce CE on this box (AMD Sempron 3000+ / 512 Ram)
I have installed the Nvidia driver but can't get the Compiz effects (such as wobbly windows and 3D cube) to work.
It's not a problem with the hardware because I have Mint 8 Gnome on another partition and compiz-fusion works fine.
Here's the terminal output of compiz-check:
Distribution: Linux Mint 8http://www.linuxmint.com/rel_helena_xfce.php
Desktop environment: Xfce
Graphics chip: nVidia Corporation NV18 [GeForce4 MX 440 AGP 8x] (rev a2)
Driver in use: nvidia
Rendering method: Nvidia
Checking if it's possible to run Compiz on your system...
Checking for texture_from_pixmap... [ OK ]
Checking for non power of two support... [ OK ]
Checking for composite extension... [ OK ]
Checking for FBConfig... [ OK ]
Checking for hardware/setup problems... [ OK ]
Everything seems fine, except the fact that no effects are apparent even after rebooting.