At the bottom of the above page, it says:

The majority of JVM errors can be resolved by performing the following
Perform a hard reset on the device.
Upgrade the RIM BlackBerry device to the latest Handheld Software.
If the error persists, attempt to run Application Loader when the device does not connect.
If further assistance is needed, please contact Customer Care.

I ran the application loader and followed the instructions on that page. Excerpts below.

IMPORTANT: Timing is critical in this process. Read through the following steps before beginning this procedure.

Procedure
Disconnect the device from the computer.
Access BlackBerry Desktop Manager, then select Application Loader.
Click Next.

Perform a hard reset on the device.
IMPORTANT: Reconnect the device before it completes the reset, then perform the following:
NOTE: If these steps are not completed before the device finishes resetting, the Application Loader will not detect the device.
If using a USB connection, wait until the drop-down list on the Communication Port Selection window changes to USB-PIN, then click Next…

See the rest.

As I said in my blog post, I had to quickly hit the next button a few times. Timing is important.

Let me know how it turns out!

So I googled this error (JVM error 517) and found your blog. I am desperately trying to fix my blackberry with this exact problem. Do you remember what you did? I can’t find information anywhere (at AT&T, Google, etc) and they won’t help because it’s just over a year old… any information you could give would be very much appreciated!

Thanks!