[Denich]

Я попробЫвал поискать то в /var/log/XFree86.0.log (там есть ещё XFree86.1.log)
вот что нашёл, что может относиться к проблеме:
(II) NVIDIA(0): Not using mode "640x480" (no mode of this name)
(II) NVIDIA(0): Not using mode "1600x1200" (width too large for virtual size)
(II) NVIDIA(0): Not using default mode "1400x1050" (width too large for virtual size)
(II) NVIDIA(0): Not using mode "1280x1024" (height too large for virtual size)
(WW) NVIDIA(0): Not using mode "1280x960" (width 1280 is larger than
(WW) NVIDIA(0):      EDID-specified maximum 1024)
(WW) NVIDIA(0): Not using mode "1152x864" (width 1152 is larger than
(WW) NVIDIA(0):      EDID-specified maximum 1024)
(WW) NVIDIA(0): Not using mode "1152x768" (width 1152 is larger than
(WW) NVIDIA(0):      EDID-specified maximum 1024)
(WW) NVIDIA(0): Not using mode "700x525" (height 1050 is larger than
(WW) NVIDIA(0):      EDID-specified maximum 768)
(WW) NVIDIA(0): Not using mode "640x512" (height 1024 is larger than
(WW) NVIDIA(0):      EDID-specified maximum 768)
(WW) NVIDIA(0): Not using mode "576x384":
(WW) NVIDIA(0):   horizontal sync start (589) not a multiple of 8
(WW) NVIDIA(0): Not using mode "360x200":
(WW) NVIDIA(0):   horizontal sync start (378) not a multiple of 8
(**) NVIDIA(0): Validated modes for display device CRT-0:
(**) NVIDIA(0):      Default mode "1024x768": 78.8 MHz, 60.1 kHz, 75.1 Hz
(**) NVIDIA(0):      Mode "800x600": 65.0 MHz, 65.0 kHz, 102.8 Hz
(**) NVIDIA(0):      Default mode "1024x768": 75.0 MHz, 56.5 kHz, 70.1 Hz
(**) NVIDIA(0):      Default mode "1024x768": 65.0 MHz, 48.4 kHz, 60.0 Hz
(**) NVIDIA(0):      Default mode "832x624": 57.3 MHz, 49.7 kHz, 74.6 Hz
(**) NVIDIA(0):      Default mode "720x400": 35.5 MHz, 37.9 kHz, 85.0 Hz
(**) NVIDIA(0):      Default mode "640x350": 31.5 MHz, 37.9 kHz, 85.1 Hz
(**) NVIDIA(0):      Default mode "512x384": 39.4 MHz, 60.1 kHz, 75.1 Hz (D)
(**) NVIDIA(0):      Default mode "512x384": 37.5 MHz, 56.5 kHz, 70.1 Hz (D)
(**) NVIDIA(0):      Default mode "512x384": 32.5 MHz, 48.4 kHz, 60.0 Hz (D)
(**) NVIDIA(0):      Default mode "416x312": 28.6 MHz, 49.7 kHz, 74.7 Hz (D)
(**) NVIDIA(0):      Default mode "400x300": 28.1 MHz, 53.7 kHz, 85.3 Hz (D)
(**) NVIDIA(0):      Default mode "400x300": 24.8 MHz, 46.9 kHz, 75.1 Hz (D)
(**) NVIDIA(0):      Default mode "400x300": 25.0 MHz, 48.1 kHz, 72.2 Hz (D)
(**) NVIDIA(0):      Default mode "400x300": 20.0 MHz, 37.9 kHz, 60.3 Hz (D)
(**) NVIDIA(0):      Default mode "400x300": 18.0 MHz, 35.2 kHz, 56.3 Hz (D)
(**) NVIDIA(0):      Default mode "320x240": 18.0 MHz, 43.3 kHz, 85.2 Hz (D)
(**) NVIDIA(0):      Default mode "320x240": 15.8 MHz, 37.5 kHz, 75.0 Hz (D)
(**) NVIDIA(0):      Default mode "320x240": 15.8 MHz, 37.9 kHz, 72.8 Hz (D)
(**) NVIDIA(0):      Default mode "320x240": 12.6 MHz, 31.5 kHz, 60.1 Hz (D)
(**) NVIDIA(0):      Default mode "320x175": 15.8 MHz, 37.9 kHz, 85.3 Hz (D)
(II) NVIDIA(0): Virtual screen size determined to be 1024 x 768
(**) NVIDIA(0): Display dimensions: (280, 210) mm
(**) NVIDIA(0): DPI set to (92, 92)
(II) Loading sub module "fb"
(II) LoadModule: "fb"
(II) Loading /usr/X11R6/lib/modules/libfb.a
(II) Module fb: vendor="The XFree86 Project"
compiled for 4.3.0, module version = 1.0.0
ABI class: XFree86 ANSI C Emulation, version 0.2
(II) Loading sub module "ramdac"
(II) LoadModule: "ramdac"
(II) Loading /usr/X11R6/lib/modules/libramdac.a
(II) Module ramdac: vendor="The XFree86 Project"
compiled for 4.3.0, module version = 0.1.0
ABI class: XFree86 Video Driver, version 0.6

показалось подозрительным вот это:
(WW) NVIDIA(0): Not using mode "1152x864" (width 1152 is larger than
(WW) NVIDIA(0):      EDID-specified maximum 1024)