[TIMOB-2671] poor performance when table view row has image background

I have tried sdk 1.4.3, 1.5.2 and 1.6 on iPhone, they all showed poor performance when table view row has image background. My table has about 100 rows ( actually, it is kind of slow when it has only 20 rows too), each row has a nice image as its background. I set rowclass, prepopulated the rows into an array then set it to tableData, it is fast in simulator (of course it is fast with 12 CPUs), but it took 5 seconds even in iPhone 4. I ended up with a trick, I only set 8 rows to tableData first (user can only see first 8 anyway), then append the rest of rows to tableview with a setTimeout function. It kind of works in iPhone 4, but not good in older version of device.

I would really appreciate you look into this performance issue, since table view is most widely used UI widget.