John,

Seems greyed out?
Now it's green again, but FX still not working on either event or track.
Motion blur has red strikes through, maybe a clue?

The "Split Screen Preview" button above the preview screen (a circle that's half dark/half light.) It's a feature and you've got it set to "bypass effects". See Vol 6 #1 of my newsletters for more details.

Edward,
I've clicked the split screen view on and off and it makes no difference. Could this be a bug in VP8, I wonder?
Stymied!
Also instances of Vegas Pro 8 are taking several minutes to open.
Is there something bigger going on here?

It's not an issue in VP8 because they work fine here in VP8.

FX worked fine here earlier today, but do not function at all now regardless of split screen setting.
I've rebooted several times and no change.
When I chose an video effect, a window comes up, but it is empty save for a cursor.
The window is filled with a sort of cross hatch pattern.
Any help is much appreciated.

A couple of things I'd consider trying:

1. Reinstall Vegas to see if that helps
2. Do a system restore to something like "yesterday" when it was working.

Try resetting the program - hold down Ctrl + Shift while you start up Vegas Pro 8. When prompted, check the box that says "delete all cached app. data" and click Yes.

Thanks Edward, I'll give those a try.

After seeing your image on another forum, I now know what your issue is:

The timeline area in the dialog is resizable. Yours has now been resized to FULL SCREEN. Put the cursor between the top of the timeline and the top of the dialog box and it should turn into an up/down arrow. Click and drag DOWN to make the timeline area smaller. You should then see the effect controls appearing as you drag downward.