External monitor cant turn off into standby

Using an M4400 with Bios A11. I have it connected via an Eport to a Dell 1905FP DVI as an external monitor. I typically switch off my notebook screen.

I have set the monitor to turn off after 15 mins and never to sleep.

I've noticed that if I let my system idle and when the monitor switches off into standby, after about 5 secs or so, it turns back on ie the power light goes from orange to green. There is no image and then it switches back into standby again. The process repeats itself over and over again. If i were to do a full standby or shutdown or hibernate, there is no problem with the monitor powering down.

The crazy part about this bug is that it doesn't occur all the time. If I do a full shut down and start the computer, it usually fixes itself. but on subsequent reboots, this problem usually pops up again.

Of course I could just disable the monitor standby but I would like to save some energy.

Could I ask all those who have external monitors (particularly those with EPorts) to just see if their monitors go to standby (while the system is on) properly? and/or if anybody knows of a solution?

(Yes I've checked the cables and have updated all drivers and patched Vista)