Cube tower not falling over

I made a tower of cubes using the game engine. Next to the cubes, there is a UVsphere that flies toward the tower of cubes. I have it set to “Record Game Physics to IPO”, so I can use it in conjunction with the fluid simulator. When I press ‘P’ to start the animation, the tower of cubes falls over, and the cubes spread around:http://img204.imageshack.us/img204/3544/cubesfall.png

But, when I try to play the animation with IPO curves, this happens:http://img689.imageshack.us/img689/8967/cubesdontfall.png

As you can see, the cubes in the second picture don’t ‘separate’, as if they are all one object.

I bet you used SHIFT+D to duplicate the blocks, but didn’t remember to duplicate an object’s ipo with the object - so when you duplicated them they still have a linked IPO. From Preferences > Edit Methods:
http://www.pasteall.org/pic/show.php?id=232
The solution is to un-link the ipos by making them single-user, or just go back to the beginning, except have that IPO box checked with the rest of them.

That fixed it, thanks! Now, when the cubes fall into the ‘water’, they act strangely. When they fall in, you’d expect them to stay still at the bottom of the fluid, but instead, they move around everywhere in the fluid and go ‘crazy’. How do I fix that?