Making hybrid 5.1/6.1 DVD Navigation discs - anyone have this problem?

[Argelius]

I've successfully made a couple of the hybrid 5.1/6.1 DVD Navigation discs, up to a point.

The discs load (after battery disconnect) fine and I do have access to the Nav Bypass in the service menu.

But, when I hit the map or dest hard buttons or enter commands with the touch screen, there is a big delay between pushing the button and when the action happens -- to the point of making it essentially unusable.

It would seem my burning process is okay, since the discs are recognized and load okay.

Thus far I've tried Memorex and Verbatim discs.

Has anyone who went through trial and errors encountered this issue?

Thanks!

[gbergman]

I have a 2008 Camry with 7.1 Nav DVD.
I copied all files to a new folder and overwrote with
"loading.kwi" 5.1 found at http://www.yourfilelink.com/get.php?fid=255527

I used Verbatim DVD+R DL written at 8x using Nero
I chose new DVD-ROM (UDF) as opposed to ISO which does not support 2G+ file sizes.
Manual settings:
UDF partition type: Physical
UDF 1.02

Title copied from original DVD: 464210-0971
The car indicates "DVD Data Unreadable."

2nd attempt...
Used "automatic settings", wrote at 4x, used a different DVD/DL drive.

2 coasters and counting. What to try next????