Disk Utility 13 problem with USB drives

Question

There appears to be a problem with Disk Utility 13 (part of OS X 10.9). At least, so far as I can tell, everything traces back to this app, or possibly OS X 10.9 itself.
I recently upgraded my MacBook Air to OS X 10.9 (reformatted hard drive, installed system from scratch, updated with all the latest Apple updates). I pre-checked all my third party software to make sure it was 10.9 compatible before installing it after the system cleanup, so everything I’m running supposedly has been approved as safe for 10.9. But I’m seeing a problem formatting USB drives that I do not encounter when running under 10.8.
I have a Seagate STAA500101 (“FreeAgent GoFlex”) drive connected via Seagate’s USB3 adapter that I’ve used for some time as a Time Machine backup. Post-overhaul, I decided to erase the backup and start fresh. When I attempt to format it (single GUID partition) with Disk Utility, I see the following messages go by:
Formatting disk1s2 as Mac OS Extended (Journaled) with name Untitled 1
Could not mount disk1s2 with name (null) after erase
Then there’s a pause, and the format appears to conclude fine. But if I run a “Verify Disk” immediately, I get this:
Verifying partition map for “Seagate FreeAgent GoFlex Media”
Checking prerequisites
Checking the partition list
Checking for an EFI system partition
Checking the EFI system partition’s size
Checking the EFI system partition’s file system
Checking all HFS data partition loader spaces
Volume  on disk1s2 has 0 bytes of trailing loader space and it needs 134217728 bytes
Problems were found with the partition map which might prevent booting
Error: Partition map needs repair because a data partition needs loader space.
As the drive has just been formatted, that seemed odd. I took it over to another Mac still running 10.8.5 and formatted it there — it worked just fine. Verified just fine. Took the drive back to my MacBook Air and tried to verify the disk — same failure.
I wanted to rule out bad media, so I took a Lexar 16GB USB flash drive and tried to format it with Disk Utility 13 — got the same problem.
The only success I’ve had formatting USB drives under 10.9 is to boot up into OS X Recovery. Disk Utility there formatted my Seagate drive without an error. But once I booted back into normal 10.9 operating mode, the drive once again fails to verify; it makes me leery about using it as a Time Machine backup.
I suppose it’s possible there could be some background component like Sophos causing problems when formatting drives, but if I format a drive via OS X Recovery or another Mac under 10.8, that wouldn’t explain why the drives fail to verify.
Anyone got any other observations on this issue?

Answer 1

Problem resolved. I'm posting this note for anyone else who might run into this situation and come across this discussion.
It actually did turn out to be Sophos -- Cloud, that is. I'd been using Sophos' free Mac antivirus software on a variety of systems but forgot that I was now testing out Sophos Cloud on my own MacBook, which is their new endpoint solution, and supposed to be compatible with OS X 10.9 (although the Mac version is listed as "beta") Sophos Cloud includes a new feature called Device Control which allows you to create a company-wide policy to control access to hardware such as USB drives, optical drives, etc. But apparently it's still pretty buggy. I had my Device Control configured with the default setting of "monitor but do not block" but it was most definitely gumming up the system. With Sophos Cloud installed, here's what happens if I try to run "Verify Disk" on any attached drive. Note on the left side how "disk2s2" shows as a sub-volume for each hard drive.
So if I uninstall Sophos Cloud, reboot and rescan, here's what I get:
Works fine. Note that the "disk2s2" subvolumes are also gone. This is the way Disk Utility also appears on a 10.8 or 10.9 system, even if you have the standard free Sophos for Mac software installed. It's only Sophos Cloud that's not playing nice. It also appears to have stopped me from being able to play DVDs from an attached Apple USB SuperDrive -- that problem was likewise solved by removing Sophos Cloud.