Car charger does not work on iPhone 3G

Bought following accessories for iPhone 3G:

• Silicon Case Cover from ebay $5.49
• USB charging/sync cable from www.usbfever.com for $3
• USB Car charger from www.dealextreme.com for $2.58 (not working on iPhone 3G!

All three items are shipped from HongKong. However, the car charger does not change iPhone charging icon. I am not sure if it is really charging or not. Since it seems can provide power to the phone. I also saw a forum discussing this issue: "iPhone 3G incompatiable with many iPod accessories". What a bad business/engineering practice from Apple!