U3 Dock freezes Mac when idle

I just got a plugable U3 hdd docking station and it’s freezing up my computer. It’s connect via USB 2.0 to an iMac with OSX 10.5.8. The U3 has version 25.80 on it. It works fine when I’m writing to the drive, but once the drive is idle for a little, the whole computer locks up. I have to cycle the doc off/on to have it move out of the lock. At this point I’m just keeping it off. Any ideas or things to test?

Hi benjiprice

Thanks for contacting us about you U3 Hard Drive Docking station freezing up. Can you tell me a little more information about the disk you’re using such as what size, and what type of file system? Can you try the dock/disk combination with another computer? Another step to try is to defragment your drive, here’s a link on how to do that:

Apple Support Article on Defragmenting your Mac’s hard drive

Let me know if you see any improvement here and we’ll figure out next steps.


I have the same or similar issue – usb2, 10.5.8, though I don’t know what version firmware. My disk’s a 1.5T Seagate Barracuda.

I noticed this while I was using Premiere – at a certain point the program would just lock up, get nothing but a spinning wheel, and force-quitting applications wouldn’t work, either. I finally realized that, if the app was locked up, as soon as I switched the dock off, the app would immediately become responsive. (or if I’d tried to force quit, the app finally force quit.)

I wasn’t saving files directly on it, but I’m guessing the programs that had problems were ones that occasionally look at hard drives (finder, and premiere and flash both have media browsers that probably look at all drives occasionally).

Hi Spinn,

Can you tell me what make and model of dock you have?


Oh yeah, I didn’t say because it sounds the same as benjiprice’s…it’s USB3-SATA-U3.

Also, firmware’s probably old because I bought it a few months ago, only really started using it in the last couple weeks. I can try to figure out how to upgrade that, but it’s a bit of a hassle (as I’m on a Mac).

Also, that defrag link you gave is for old systems; the new one is


…although that pretty much says, don’t bother.


It’s interesting that you both have 10.5.8 and are having similar issues.

benjiprice – can you get into System Profiler when you are in the lock up state? I’m guessing not because you stated you had to hard reset. Is it repeatable?

Spinn – do you see a situation where your machine locks up solid? Also, when you get into the frozen state, can you see the USB Mass Storage device and the file system information in System Profiler?

Regarding the firmware, at this time there’s only an updater program available for Windows. While it’s always a good idea to have the latest firmware, because this firmware update was mainly to address USB3.0 issues it’s not likely that it will help.

We want to learn whether the dock is disconnecting or if the drive is just going to sleep. Let us know if you can see the drives when the programs are hung up, we’ll figure out what’s next.

Thanks for your patience!


I haven’t had a full system lockup, no. Seems to affect applications in turn (that’s why I was guessing it’s about disk access).

I’ve just turned it on now and I’ll wait to see when it does it again; when/if it does, I’ll check the profiler. Oh, though speaking of which, it tells me “version: 22.47”, which I’m guessing is firmware version?

I do remember the disks were still visible in Finder at least, but I don’t know if that really meant they were still there. Trying to eject them wouldn’t work…hm I don’t remember whether that made the Finder unresponsive as well, I’ll test when it comes up again.

And re:patience, thanks for yours. I used to work in support, so I’ve felt your pain.

Hi Spinn,

You are correct, Version 22.47 is the firmware revision. Is it possible for you to find a Windows machine on which you can have admin access so you can update to 25.80. If not, or if after updating the firmware you’re still seeing issues, contact us at support@plugable.com and we’ll get you fixed up.

Here’s the link to the update instructions:


Thanks again,