Playback of project on external USB disk does not work

Dear forum members,

when I try to playback a project (quite small, just a handfull tracks) with Cubase Elements 6.0.7 (64-bit Version) from an external USB harddrive, I can hear noisy dropouts (the level meters for some tracks freeze & the VST-power meter for DISK periodically jumps to 100% (the meter for ASIO looks normal)) and after a few seconds Cubase crashes. It happens with both USB 2.0 connections and drives as well as USB 3.0.

When I copy the identical project to an external eSATA disk (or also an internal SATA) everything works fine. Moreover, the same project works fine when I run it from the same USB 3.0 drive on my MAC Book.

Here is some information on my PC:

Motherboard: ASUS P6T with Intel X58 Chipset (newest BIOS and chipset drivers from ASUS website installed)
Intel Core i7 CPU 920 @ 2.67GHz
Windows 7 Ent. SP1 64bit (with all updates)

I should also add that “normal” data transfer between the USB 3.0 drive and the PC looks normal (about as fast as transfering files between SATA disks). People tell me that even USB 2.0 should be fast enough. I mean even playback of full HD video files works fine, just that problem with Cubase.

Did anybody experience the same problem or does anyone have an idea how to fix this (e.g. any settings in BIOS, OS, or Cubase)?

Thanks for any hints to find a solution.