Hi there.

I've recently bought an external HDD, it works fine on my Ubuntu box.

The problem is that my Slackware box doesn't recognize it. I'm assuming it's my custom kernel's fault. After searching on the internet, I came to the conclusion that the necessary modules for the USB HDD are these:
scsi_mod sd_mod (and other USB-related modules that I already had, needed for a pen drives: usbcore, usb_storage, ehci_hcd, uhci_hcd)

It didn't work, so I tried compiling some more modules: sg (scsi generic), ohci_hcd... nothing. Oh, and another funny thing: the hdd doesn't even show up in lsusb.

The kernel version I'm using:
Linux bestia 2.6.20.6 #1 PREEMPT Tue Apr 10 11:28:14 CEST 2007 i686 pentium4 i386 GNU/Linux
Distro: Slackware Linux 11.0

Am I missing something? Can somebody help me? Thanks in advance.

Here's my lsmod | grep usb output with an external usb drive connected and mounted:

$ lsmod | grep usb
usb_storage 98400 2
usbcore 138112 4 usb_storage,ehci_hcd,uhci_hcd
scsi_mod 144904 5 sg,usb_storage,sd_mod,ahci,libata

ahci and libata are for sata and not relevant to your problem. Check your lsmod output and see if you are missing anything.