Ok, I think I've solved it through some scripting.
Unplugging and re-plugging the dock seems to always work in bring the display to the external monitor. Why oh why it doesn't work when you sleep/wake is beyond.
Anyway. Plugging/unplugging is the same as disabling/re-enabling the USB Composite Port. I also discovered that disabling/enabling the "Dynadock U3.0" under USB Display Adaptors has the same effect. The picture freezes when you disable and then you can re-enable via the laptop screen.
What I did is get devcon.exe for Windows 7 which allows you to manage devices from the command line.
http://social.technet.microsoft.com/...icles/182.aspx
I then dump the hwids and found the hwid for the "Dynadock U3.0" and put it in a script. i.e.
c:\devcon\devcon.exe disable "USB\VID_17E9&PID_4305&REV_0015&MI_00"
c:\devcon\devcon.exe enable "USB\VID_17E9&PID_4305&REV_0015&MI_00"
And this worked perfectly. If you get no matching device errors despite it finding the device then you have the wrong (old I suppose) version of devcon or didn't follow the install instructions. I tried copying it out of the cab file and kept getting the error. Following the instructions from microsoft worked.
I then followed these instructions to create a script to run when the computer wakes.
http://superuser.com/questions/11380...leep-hibernate
It makes wake up a fraction slow (20 seconds) but the external monitor is always there now or so it seems with limited testing.
C