diff -Nurp VirtualBox-4.1.8_OSE-p1/src/VBox/HostDrivers/Support/linux/Makefile VirtualBox-4.1.8_OSE-p2/src/VBox/HostDrivers/Support/linux/Makefile
--- VirtualBox-4.1.8_OSE-p1/src/VBox/HostDrivers/Support/linux/Makefile	2011-12-19 15:01:06.000000000 +0200
+++ VirtualBox-4.1.8_OSE-p2/src/VBox/HostDrivers/Support/linux/Makefile	2011-12-24 15:22:08.487043179 +0200
@@ -165,7 +165,7 @@ ifeq ($(KERNELRELEASE),)
  # kernel base directory
  ifndef KERN_DIR
   # build for the current kernel, version check
-  KERN_DIR := /lib/modules/$(shell uname -r)/build
+  KERN_DIR := /lib/modules/$(KERNELRELEASE)/build
   ifneq ($(shell if test -d $(KERN_DIR); then echo yes; fi),yes)
    KERN_DIR := /usr/src/linux
    ifneq ($(shell if test -d $(KERN_DIR); then echo yes; fi),yes)
@@ -194,7 +194,7 @@ ifeq ($(KERNELRELEASE),)
  # module install dir, only for current kernel
  ifneq ($(filter install install_rpm,$(MAKECMDGOALS)),)
   ifndef MODULE_DIR
-   MODULE_DIR_TST := /lib/modules/$(shell uname -r)
+   MODULE_DIR_TST := /lib/modules/$(KERNELRELEASE)
    ifeq ($(shell if test -d $(MODULE_DIR_TST); then echo yes; fi),yes)
     MODULE_DIR := $(MODULE_DIR_TST)/misc
    else
@@ -286,7 +286,7 @@ install_rpm: $(MODULE)
 else # eq ($(MAKECMDGOALS),clean)
 
  ifndef KERN_DIR
-  KERN_DIR := /lib/modules/$(shell uname -r)/build
+  KERN_DIR := /lib/modules/$(KERNELRELEASE)/build
   ifeq ($(wildcard $(KERN_DIR)/Makefile),)
    KERN_DIR := /usr/src/linux
   endif