Lighting, Light Fixtures, Ceiling and Exhaust Fans - Replacing fan with halogen lights

I thought this was going to be an easy task ...
I wanted to replace the kitchen ceiling fan with a light fixture that has four 50W halogen lamps. The fan is activated by two switches.

First problem, there are three groups of wires coming out of the ceiling, one white bunch of 4 wires, a black wire and a black wire painted white.

Using a tester, I checked that the black wire is hot and connected it to the black wire of my halogen lights and the white bunch with the white wires of the light fixture. The problem is that the light is always on! the switches do not work at all.

I then decided to replace the connection of the white wire of light fixture with the painted black wire. The switches work fine but the light does not stay on! After a few seconds it fades and switches off completely. The only way to keep it on is to only have one 50W bulb in the fixture that has four.

Any idea why this is happening? How can I fix it?

You should have used the same wires as the fan.

Something sounds wrong that you have more white wires than blacks. Normally you should have them in pairs. It sounds like you have have a improperly wired switch loop with the white coded black. If you have a switch loop the white should have been the feed to the switch, not the switched hot.

Have you tested the white coded black to see if it is switched?