How to fix my MacBook boot-up problem?

I guess I've faced with very rare issue cause I haven't seen so far anybody else on this forum who reports the same problem.

A typical situation - every morning at the office I turn on my Macbook, have to let it heat up like 20 mins after pressing power button, all this time I can see the led light lights steady, then I turn it off (I can hear like HD stops rotating) and then turn it on again holding 'Option', then wait couple minutes having a HD icon on the screen and then I hit 'Return' to let the thing to boot. This is the only way I can boot my MacBook. After this he can work any time you want with no problems. I've checked it for sure. Now, I've come through a complete hardware testing, which was performed by an Apple authorized technician, but not in a store, he was a freelancer, the testing showed no problems at all. HD, RAM, logic board are OK. As far as I can see everything clearly tells about that something has gone out of order on the motherboard.

I bought it July, 2007 and sure there is no way to change it under a guarantee, the issue began to take place this November. The reason for writing here is I just would like to know if somebody else ever had the same problem?

I tried the following so far:
1. Via Disk Utility ran Permissions+HD testing
2. Archive&Install
3. Tried other HD, RAM
4. Removed the battery
5. Tried other power supply
6. Ran Full Hardware test
7. Consulted with local technician to perform special hardware test
8. SMC reset, PRAM reset

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