I am reporting the following issue...

My system:

A2000, OS 3.2.1, V500 v2+, megachip with Agnus 8375 NTSC version (318069-11), Gold 2.16. Buddha IDE (for my cd-rom)

WHDLoad games have 'jittery/jumpy' mouse movement. I can see this in numerous games. Dungeon Master for one.

I re-flashed with Gold 2.14 and 2.15, the same issue exists.

After replacing the megachip with the original 1mb Agnus, all is fine.

The issue doesn't seem to be targeted towards 3.2.1 because it exists with Coffin as well.

I understand that you have a problem with this NTSC AGNUS.
And that the problem is gone when you use the original AGNUS.

Do you have the problem also without any accelerator?
What if you remove the Accelerator and run the WHDLOAD games?

I should have tried that. Apologies for not thinking about it.
I'll get to it on the weekend and post an update.

I don't currently have a spare 68000 processor to replace the vampire with.

I do have a spare Pistorm. With the Pistorm, the issue persists.
So it seems it is a WHDLoad compatibility problem.

You can ignore the issue. I'll raise it with the WHDLoad team.

Thank-you.