REISUB (Alt+SysRq+key) doesn't work on Slackware13.37_64, KDE

Question

Under Slackware I never used the magical REISUB, and never used KDE (I don't know if it is important). But now I installed a Slackware13.37_64 with KDE, and, as far as I know, I didn't modify anything that could modify the default REISUB behaviour. Well, it didn't work in a disastrous situation. I tried then it with the system functioning well, and it didn't work either. Is it a bug or a disabled feature? How to switch it on?

$ uname -a

Linux mysystem 2.6.37.6 #3 SMP Sat Apr 9 22:49:32 CDT 2011 x86_64 Pentium(R) Dual-Core CPU T4300 @ 2.10GHz GenuineIntel GNU/Linux

The notebook is ASUS K50IJ.

Answer 1

Apparently, it can be enabled/disabled using /proc/sys/kernel/sysrq if the kernel supports it, i.e., CONFIG_MAGIC_SYSRQ is enabled in the kernel config what should be the case for Slackware, according to this.