hi

my mouse pointer disappears from time to time
I need to restart startx to make it reappear.
I use Slackware 14.0 / xfce 4.10 / on a Acer Aspire 9300 laptop (GeForce GO 6100)

Any idea ?

Not sure, but which driver are you using: NVidia or nouveau? If nouveau, you might be better using NVidia.

it's nVidia

(root) /root>lspci
00:00.0 RAM memory: nVidia Corporation C51 Host Bridge (rev a2)
00:00.1 RAM memory: nVidia Corporation C51 Memory Controller 0 (rev a2)
00:00.2 RAM memory: nVidia Corporation C51 Memory Controller 1 (rev a2)
00:00.3 RAM memory: nVidia Corporation C51 Memory Controller 5 (rev a2)
00:00.4 RAM memory: nVidia Corporation C51 Memory Controller 4 (rev a2)
00:00.5 RAM memory: nVidia Corporation C51 Host Bridge (rev a2)
00:00.6 RAM memory: nVidia Corporation C51 Memory Controller 3 (rev a2)
00:00.7 RAM memory: nVidia Corporation C51 Memory Controller 2 (rev a2)
00:02.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1)
00:03.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1)
00:04.0 PCI bridge: nVidia Corporation C51 PCI Express Bridge (rev a1)
00:05.0 VGA compatible controller: nVidia Corporation C51 [GeForce Go 6100] (rev a2)
00:09.0 RAM memory: nVidia Corporation MCP51 Host Bridge (rev a2)
00:0a.0 ISA bridge: nVidia Corporation MCP51 LPC Bridge (rev a3)
00:0a.1 SMBus: nVidia Corporation MCP51 SMBus (rev a3)
00:0a.3 Co-processor: nVidia Corporation MCP51 PMU (rev a3)
00:0b.0 USB controller: nVidia Corporation MCP51 USB Controller (rev a3)
00:0b.1 USB controller: nVidia Corporation MCP51 USB Controller (rev a3)
00:0d.0 IDE interface: nVidia Corporation MCP51 IDE (rev f1)
00:0e.0 IDE interface: nVidia Corporation MCP51 Serial ATA Controller (rev f1)
00:10.0 PCI bridge: nVidia Corporation MCP51 PCI Bridge (rev a2)
00:10.1 Audio device: nVidia Corporation MCP51 High Definition Audio (rev a2)
00:14.0 Bridge: nVidia Corporation MCP51 Ethernet Controller (rev a3)
00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
04:05.0 Network controller: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02)
04:06.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller
04:06.2 Mass storage controller: Texas Instruments 5-in-1 Multimedia Card Reader (SD/MMC/MS/MS PRO/xD)

Yes. you have "nvidia" GPU but you still haven't said which nvidia driver.

If you are having X autodetect everything, you may need to tweak the xorg mouse settings depending on the type of mouse you have. For example, make a /etc/X11/xorg.conf.d/mouse.conf
Play around with difference Driver (such as evdev) and Protocol settings. Check /var/log/Xorg.0.log to see what gets autodetected.

If you are using nouveau driver, try using the proprietary Nvidia driver ( nvidia.com or slackbuilds.org ) as there are reports that the mouse cursor can disappear during system inactivity with the nouveau driver.

sorry (newbie)

does that gives you the answer:
(root) /root>
(root) /root>cat /proc/modules | grep nouveau
nouveau 661269 2 - Live 0xf95b5000
mxm_wmi 1093 1 nouveau, Live 0xf9471000
ttm 45384 1 nouveau, Live 0xf945c000
drm_kms_helper 22825 1 nouveau, Live 0xf943e000
drm 151850 4 nouveau,ttm,drm_kms_helper, Live 0xf9400000
i2c_algo_bit 4543 1 nouveau, Live 0xf89a8000
video 9938 1 nouveau, Live 0xf8929000
i2c_core 16454 6 videodev,nouveau,drm_kms_helper,drm,i2c_algo_bit,i2c_nforce2, Live 0xf8887000
hwmon 1033 3 nouveau,k8temp,thermal_sys, Live 0xf87a2000
button 3665 1 nouveau, Live 0xf873d000
(root) /root>
(root) /root>
(root) /root>cat /proc/modules | grep -i nvidia
(root) /root>
(root) /root>
(root) /root>

You might want to give the nvidia driver a try. You will need the 304.x legacy driver for that GPU.