I am getting system errors at boot up, not alwasy but often. Checking in the logs, it seem to come from my Graphic card. It is an Asus 8400GS. Not that it causes any issue, but I would like to solve it and make sure it does not become an issue at one point in time.

From the /var/crash I have this file: nvidia-331.0.crash

Code:
ProblemType: PackageDKMSBuildLog:
 DKMS make.log for nvidia-331-331.113 for kernel 3.13.0-45-generic (x86_64)
 Sun Feb  1 12:48:02 EST 2015
 NVIDIA: calling KBUILD...
 make[1]: Entering directory `/usr/src/linux-headers-3.13.0-45-generic'
 test -e include/generated/autoconf.h -a -e include/config/auto.conf || (        \
     echo >&2;                            \
     echo >&2 "  ERROR: Kernel configuration is invalid.";        \
     echo >&2 "         include/generated/autoconf.h or include/config/auto.conf are missing.";\
     echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";    \
     echo >&2 ;                            \
     /bin/false)
 mkdir -p /var/lib/dkms/nvidia-331/331.113/build/.tmp_versions ; rm -f /var/lib/dkms/nvidia-331/331.113/build/.tmp_versions/*
 make -f scripts/Makefile.build obj=/var/lib/dkms/nvidia-331/331.113/build
   cc -Wp,-MD,/var/lib/dkms/nvidia-331/331.113/build/.nv.o.d  -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/4.8/include  -I/usr/src/linux-headers-3.13.0-45-generic/arch/x86/include -Iarch/x86/include/generated  -Iinclude -I/usr/src/linux-headers-3.13.0-45-generic/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/usr/src/linux-headers-3.13.0-45-generic/include/uapi -Iinclude/generated/uapi -include /usr/src/linux-headers-3.13.0-45-generic/include/linux/kconfig.h -Iubuntu/include  -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -fno-delete-null-pointer-checks -O2 -m64 -mno-mmx -mno-sse -mpreferred-stack-boundary=3 -mtune=generic -mno-red-zone -mcmodel=kernel -funit-at-a-time -maccumulate-outgoing-args -fstack-protector -DCONFIG_X86_X32_ABI -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -DCONFIG_AS_FXSAVEQ=1 -DCONFIG_AS_AVX=1 -DCONFIG_AS_AVX2=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -Wframe-larger-than=1024 -Wno-unused-but-set-variable -fno-omit-frame-pointer -fno-optimize-sibling-calls -fno-var-tracking-assignments -pg -mfentry -DCC_USING_FENTRY -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fconserve-stack -Werror=implicit-int -Werror=strict-prototypes -DCC_HAVE_ASM_GOTO -DNV_MODULE_INSTANCE=0 -DNV_BUILD_MODULE_INSTANCES=0 -UDEBUG -U_DEBUG -DNDEBUG -I/var/lib/dkms/nvidia-331/331.113/build -Wall -MD -Wsign-compare -Wno-cast-qual -Wno-error -D__KERNEL__ -DMODULE -DNVRM -DNV_VERSION_STRING=\"331.113\" -Wno-unused-function -Wuninitialized -mno-red-zone -mcmodel=kernel -DNV_UVM_ENABLE -D__linux__ -DNV_DEV_NAME=\"nvidia\"  -DMODULE  -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(nv)"  -D"KBUILD_MODNAME=KBUILD_STR(nvidia)" -c -o /var/lib/dkms/nvidia-331/331.113/build/.tmp_nv.o /var/lib/dkms/nvidia-331/331.113/build/nv.c
 In file included from include/uapi/linux/stddef.h:1:0,
                  from include/linux/stddef.h:4,
                  from /usr/src/linux-headers-3.13.0-45-generic/include/uapi/linux/posix_types.h:4,
                  from include/uapi/linux/types.h:13,
                  from include/linux/types.h:5,
                  from include/uapi/linux/capability.h:16,
                  from include/linux/capability.h:15,
                  from include/linux/sched.h:13,
                  from include/linux/utsname.h:5,
                  from /var/lib/dkms/nvidia-331/331.113/build/nv-linux.h:44,
                  from /var/lib/dkms/nvidia-331/331.113/build/nv.c:13:
 /usr/src/linux-headers-3.13.0-45-generic/arch/x86/include/asm/uaccess.h: In function \u2018copy_from_user\u2019:
 /usr/src/linux-headers-3.13.0-45-generic/arch/x86/include/asm/uaccess.h:612:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (likely(sz < 0 || sz >= n))
                           ^
 include/linux/compiler.h:152:40: note: in definition of macro \u2018likely\u2019
  # define likely(x) __builtin_expect(!!(x), 1)
                                         ^
 /usr/src/linux-headers-3.13.0-45-generic/arch/x86/include/asm/uaccess.h: In function \u2018copy_to_user\u2019:
 /usr/src/linux-headers-3.13.0-45-generic/arch/x86/include/asm/uaccess.h:630:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (likely(sz < 0 || sz >= n))
                           ^
 include/linux/compiler.h:152:40: note: in definition of macro \u2018likely\u2019
  # define likely(x) __builtin_expect(!!(x), 1)
                                         ^
 mv: cannot stat \u2018/var/lib/dkms/nvidia-331/331.113/build/.tmp_nv.o\u2019: No such file or directory
 make[2]: *** [/var/lib/dkms/nvidia-331/331.113/build/nv.o] Error 1
 make[1]: *** [_module_/var/lib/dkms/nvidia-331/331.113/build] Error 2
 make[1]: Leaving directory `/usr/src/linux-headers-3.13.0-45-generic'
 NVIDIA: left KBUILD.
 nvidia.ko failed to build!
 make: *** [nvidia.ko] Error 1
DKMSKernelVersion: 3.13.0-45-generic
Date: Sun Feb  1 12:49:07 2015
Package: nvidia-331
PackageVersion: 331.113-0ubuntu0.0.4
SourcePackage: nvidia-graphics-drivers-331
Title: nvidia-331 331.113-0ubuntu0.0.4: nvidia-331 kernel module failed to build
and from the apport.log

Code:
ERROR: apport (pid 2827) Sun Feb  1 14:34:33 2015: called for pid 2822, signal 11, core limit 0
ERROR: apport (pid 2827) Sun Feb  1 14:34:33 2015: executable: /usr/bin/xfsettingsd (command line "xfsettingsd")
ERROR: apport (pid 2827) Sun Feb  1 14:34:33 2015: executable version is blacklisted, ignoring
Thanks