Monitor black at boot up...

My 19" flat-screen desktop monitor (Samsung SyncMaster 931BF) has trouble coming on in the mornings when I boot the computer up. I can see the blue "standby" light (at the on/off button in the lower right corner) is on, and the computer itself is on, but the screen remains black.

When I turn the monitor off (for a few seconds) then turn it back on, the screen will come on for a second or two, then go black again. Also, when it comes on (for a second), it's dimmer than usual.

So, I repeat the above sequence 4 or 5 times and finally it stays on and gets to its normal brightness. This morning it took almost 20 times before it stayed on and I'm concerned it's getting worse...