CF64 on Server 2008x64 breaks pretty much everything else, how to fix?

I just installed CF64 on a WinServer2008x64 machine. Previously a whole array of classic ASP and ASP.Net apps were functioning, after the CF install they're not.

I'm getting an http 500 on everything not coldfusion. I believe it's a mapping issue. CF seems to have dropped a wildcard handler mapping into the IIS config

Module IsapiModule Notification ExecuteRequestHandler Handler AboMapperCustom-89420 Error Code 0x800700c1

The upside (if you can call it that) is that the CF install took and seems to be functioning. It appears to have dropped in

Well, scratch that. I don't know what fixed it but I pulled off the "AboMapperCustom-89420" wildcard handler mapping and re-created the affected websites. That seems to have done it.