FlashWindow Doesn't Work On Minimized Program

Environment: VC++ 6.0, Win7

I'm trying to use CWnd::FlashWindow() to flash the program's TaskBar icon. I'm using the system timer to call FlashWindow() six times (about every second).

When the program is in the foreground FlashWindow() works OK. However, when the program is minimized or not in the foreground (hidden) the TaskBar icon changes state only once and does not flash.

Yeah, I know VC++ 6.0 is old. I can't use FlashWindowEx() because my libraries don't support it and I haven't found any place where I can download the updated libraries.

Any thoughts?