A4000D Agnus?

[Ilwrath]

Most likely just a software screwup with your workbench install.  SysInfo just reports it's best guess of what it sees.  Wasn't there another thread about this happening around here, recently?

Check your setpatch version.
Check your monitor driver version.  (and make sure it's compatible with AGA, and make sure it's compatible with the version of Workbench you're running, and make sure it's compatible with your setpatch...)
Make sure you don't have an L:system-configuration

[Ilwrath]

How can I tell if the version of setpatch I have is compatible with the version of workbench I have? How many other versions of setpatch are there?

A lot.  A whole lot of versions of setpatch are floating around.

You seem to have a fairly new one, but I'm not sure it's the newest.  You might want to check the boingbag archive and make sure the version you're running is AT LEAST at that level, since you are running BB2.

Also, make sure you've got the proper "AmigaOS ROM Update" file in your DEVS: for that version of SetPatch.

Also, do the same for your PAL monitor driver.

Also, you may want to try deleting ENVARC:sys/screenmode.prefs and overscan.prefs.  (The screenmode and overscan tools will make new ones when you click "SAVE", anyhow.)

If everything still checks out, try booting the system with no startup-sequence and from the basic shell, try c:setpatch and see what output you get from it.  There shouldn't be any errors, and there should be a line about "Advanced Graphics Enabled" or "AGA Screens Enabled" or something like that.