Well, I come back
I had the same card and the same problem about a year ago, and solved it.
Go to
www.guru3d.com "Downloads" section, "Videocards - Overclocking & Tweaking" category, and search for Coolbits (if you are using Detonator drivers) or ForceWare Coolbits 2.0 (if you are using ForceWare drivers). Download it.
This thing adds a registry value so you can change some NVIDIA settings like clock frequency. So do right click in desktop, Properties, Configuration, Advanced options, Geforce 4MX..., and search a new setting like overclocking or something like that (I have it as "Clock Frequency Settings"). Change the values there, especially for core clock, to something like 234 MHz, and leave memory clock, or you can up it a bit (I have mine at 321 MHz). Accept (the first time I think you have to reboot) and play.
This is what I am doing. If I play with core at 275 MHz (predetermined) I have the same bad screenshots and performance. Now with 234 I can play. I recommend you to go slowly, first reduce 15 MHz, then 10, until you have the value. And I have to say that it is an important setting, and an error may cause really bigger problems. Do it with care.
And, obviously, this isn't a great card (I am now searching prices for better cards to buy), but it can play NBA 2005 (i think is the same with 06)