The Strangest Thing pleex Help!!!

Ok This is about the strangest thing thats happened to me. The problem started about 3 days ago. I have not installed any hardware or software on the system for like a month so don't know what caused this.

When I first boot up in the morning, the mobo fails to post, no beeps and no video. The fans and the leds turn on the it gets stuck. After like 3-5 mins or so, when I restart it, it boots up normally and works fine. The strange thing is that it only does this on the first turn-on of the day. After the first boot, it works like a charm no matter how many times I reboot. Also there is no problems with stability when running (ran sandra burnin for 2 hrs no probs). So I dont know wtf is wrong. Can someone Please help! Thank you.

System:
Soyo dragon plus
Athlong xp 1800+
512mb crucial 2100
Gainward Ti4400 Golden Sample
(nic and sound on the mobo)
External cable modem
MyHD mdp100 hdtv tuner card
300w ps.


<b>If it aint broke, <font color=red> overclock </font color=red> it</b>.

In my opinion it is the power supply. I friends pc had a similar problem. When he turns on the PC the blow fans turn for a split second then nothing, everything dead. Although, your's could be started after the first try his wouldn't start no matter how many attempts. He changed the PSU and everything was back to normal.