On ESXi 4.1 Update2, I have started building a VM and have attached an ISO to the virtual CDROM and it is failing with the following from the vmware.log:
Oct 24 12:05:01.365: vcpu-0| CDROM: Mode Sense for Unsupported Page 0x1B
Oct 24 12:05:01.365: vcpu-0| SCSI DEVICE (ide0:0): MODE SENSE(10) for unsupported page 0x1b
Oct 24 12:05:01.494: vcpu-0| CDROM: Emulate GET CONFIGURATION RT 0 starting feature 0
Oct 24 12:05:01.494: vcpu-0| CDROM: Emulate GET CONFIGURATION RT 0 starting feature 0
Oct 24 12:05:01.494: vcpu-0| CDROM: Emulate GET CONFIGURATION RT 0 starting feature 0
Oct 24 12:05:01.494: vcpu-0| CDROM: Accepting Event Status Notification 0
Oct 24 12:05:01.494: vcpu-0| CDROM: Failed on unsupported 0x4a event 0
Oct 24 12:05:01.495: vcpu-0| CDROM ide0:0: CMD 0x4a (*UNKNOWN (0x4a)*) FAILED (key 0x5 asc 0x24 ascq 0)
Oct 24 12:05:01.495: vcpu-0| CDROM: Unknown command 0xA4.
Oct 24 12:05:01.495: vcpu-0| CDROM ide0:0: CMD 0xa4 (*UNKNOWN (0xa4)*) FAILED (key 0x5 asc 0x20 ascq 0)
I have tried changing this back and forth from ide1:0 and ide0:0 to no avail. I have seen other posts from years ago with similar issues, but have not found a solid resolution. I can't get the OS to start loading on the vmdk, so I am kind of stuck. I am having to do all of this from cli for DR test preflight tests. 
The server is an IBM xSeries which actually has the hyper-v onboard for install, but I went ahead and downloaded and installed from disk. Any and all help is greatly appreciated.
Ok. So I finally went the vSphere route connected directly to the host and I still see the same thing in the vmware.log file, but the guest OS ISO is installing just fine. I am not sure why this wouldn't work over VNC. Anyone else experience this? Anyway...I'm off to the races with it now!
Thanks!
excerpt for VNC access:
RemoteDisplay.vnc.enabled = "True"
RemoteDisplay.vnc.port = "5901"
RemoteDisplay.vnc.password = "secured-by-izz"
Anyway...again, vSphere works connected to the client. I had no idea I didn't need vCenter.