Xbox button flashes green only

[kosmiq]

Never heard of flashing green only... And as much as I can remember the following flashes is possible:

Solid Green - Problem: None (XBOX is in perfect shape) - Solution: (none)

Orange Flashing - Problem: Too much heat. - Solution: Turn the XBOX off for a while.

Green Flashing - Problem: None (just means DVD is in use) - Solution: (none)

Green, Orange, Green, Orange - Problem: No detected video pack. - Solution: Check the connection of the video pack.

Solid Red - Problem: There is an error with the DVD tray. - Solution: Get the tray into the proper position.

Red, Orange, Red, Orange: Problem: Part of the installed RAM is not functional. - Solution: Replace the RAM.

Long Red and Green - Problem: Hard drive does not function accordingly. - Solution: (mostly) Replace the hard drive.

Red and Long Green - Problem: DVD drive does not function accordingly. - Solution: (mostly) Replace the DVD drive.

Green, Orange, Green, Orange - Problem: USB bus crash. - Solution: Remove some USB devices.

Flashing RED - corrupt eeprom

Solid Green, no video/sound/eject - corrupt TSOP (known as console coma)

So it seems as your xbox is for some reason reading from the dvd-rom judging by the flashing codes.
You can try too start the xbox and during boot press the eject button and see if it will continue the booting.
Are you getting Video/sound? Did you do anything the last time you powered down?
Please describe the problem a little more.