Comment 6 for bug 359350

https://bugs.freedesktop.org/show_bug.cgi?id=22265
has a very similar problem, his bugreport is the following:

Video Card is a GeForce3 Ti 500

Using the nouveau driver in my xorg.conf I get a blank screen after booting the
system. (Text Console works)

Looking at Xorg.0.log the following lines are found

(II) NOUVEAU(0): BMP BIOS found
(II) NOUVEAU(0): BMP version 5.20
(II) NOUVEAU(0): Bios version 03.20.00.20
(II) NOUVEAU(0): Found Display Configuration Block version 1.5
(!!) NOUVEAU(0): Raw DCB entry 0: f0003f00 000088b8
(!!) NOUVEAU(0): Raw DCB entry 1: f2205002 ffffffff
(EE) NOUVEAU(0): Unknown DCB 1.5 entry, please report

Backtrace:
0: /usr/bin/Xorg(xorg_backtrace+0x3b) [0x812d07b]
1: /usr/bin/Xorg(xf86SigHandler+0x9e) [0x80c061e]
2: [0xc1a400]
3: /usr/lib/xorg/modules/drivers//nouveau_drv.so(NvSetupOutputs+0x3b)
[0x1f16ab]
4: /usr/lib/xorg/modules/drivers//nouveau_drv.so [0x1e8c4a]
5: /usr/bin/Xorg(InitOutput+0x4e9) [0x80a8e39]
6: /usr/bin/Xorg(main+0x1cb) [0x806b92b]
7: /lib/libc.so.6(__libc_start_main+0xe6) [0xaa5a66]
8: /usr/bin/Xorg [0x806afa1]

Fatal server error:
Caught signal 11. Server aborting