currently running Slackware64 14.1 with kernel 3.10.36 and am having quite an annoying issue where I have a Lenovo W520 notebook that has a eSATA port that also acts as a USB 2.0 port. in the past, not sure how long ago, this eSATA port worked flawlessly with my external HDD that has a eSATA connection. since then I've switched to a USB 3.0 housing for the external drive until recently when the board for the housing failed and it wouldn't behave reliably so I've moved back to this eSATA housing and now it won't spit out any messages in 'dmesg' to show there's life when I connect the drive. tried all the combinations of turning on then plugging, plugging then turning on, etc. to no avail. the only way to get this drive to read is to have it on and connected when I restart my computer... but since I rarely do that, this drive is a pain! weird thing is once I get it going after a reboot, if I turn off the device after a while it stops being recognized again! anyone have any suggestions?

Sounds similar to the problem many of us saw with our Acer AOA150 netbooks that would only recognize an SD card in the slot if it was present at boot. Turned out to be a kernel driver issue. If it used to work, you could always try going back to an older kernel.