I too am programming on the Mac (MBP 17") with VMware Fusion (3.0.2) in Snow Leopard (10.6.3) and have issues with MX-900 connectivity, although in a different way than any posts detail here. I've read this post and 3 others about Mac / VPC issues. DSP81 has the right info. I have reworded the process with complete instructions and have included a history trail for clarity:

1. After successful programming in the MX-900 stand-alone editor, I attempted a download.
2. Connected the MV-900 and got the obligatory usb connection beep from the remote.
3. Tried the download and got the "unable to conect sc-1, unable to connect ct1"
4. Searched Remote Central for help and found this post. Tried to implement DSP81's advice by adding the "usb.generic..." text string to my Virtual Machine (VM) but could not find the VM. Once I found it I did not know what to do. After more research and head scratching, I figured it out. Here's how I did it:
5. (How to access a VMWare Fusion "Virtual Machine" and make settings changes) My "Virtual Machine" was located in the Documents folder:

<< Before doing this, quit Fusion and suspend the Virtual Machine >>

a) Locate: Documents/Virtual Machines/[your virtual machine's name].vmwarevm
b) Right click (or control click) on this item and click on "Show Package Contents" and another finder window will open with a bunch of items in it.
c) One of those items will be called "[your virtual machine's name].vmx" This is the item where changes to the VM can be made.
d) Select that item, right click and do an "Open With" and select Text Edit to open it and do the editing.
e) Add the text string: usb.generic.allowHID = "TRUE" (I added it to the bottom after doing a return to create a new line).
f) Then save the Text Edit document. It should save it right back to the folder where you found it. Then quit Text Edit.

<< Then restart your VM >>
<< Put the VM in Full Screen mode. >>

Launch your URC editor and connect or reconnect your remote. Check to see that the remote shows up as connected in the Fusion Settings area and/or look at the USB icons down at the bottom to verify that a URCHID... is listed as connected to one of your USB ports.

6. Then do your download. THIS IS WHERE I HAVE TROUBLE: During the download process I have initial USB connection with the remote at the beginning, then the remote disconnects and reconnects to the computer several times during the download. The problem occurs when the remote attempts to reconnect after the first disconnection. It fails, and the USB connection "times out" or otherwise prevents a reconnection. The remote is then frozen in it's interrupted download state until reboot (remove batteries, restart). The download operation does not succeed.

I guess it's by URC design that the MX-900 does this on again / off again USB connection procedure as it's always behaved this way when I program on a PC, what I don't know is if there is some way to adjust this event so it doesn't sink the download, or some other feature of the Mac or VM that can be tweaked to get success.

Any Ideas? Thanks. Please send email reply copy to [email protected]

<< UPDATE AS OF DECEMBER 8 2010 >>

VMware Fusion has updated twice since I wrote the entry above. Now version 3.1.2 seems to treat USB connected devices quite better. Just today I programmed a brand-new MX 900 in this way:
1) Launch Fusion, launch MX 900 programming software, connect remote
2) Go to virtual machine/USB and "connect URCHID"
3) Download program into remote and part way through the system update the program will fail as the remote disconnects and then attempts to reconnect.
4) Disconnect remote (it will be in a "hung" state), reboot by removing a battery and reinserting. Connect remote again
5) Repeat step two. Repeat download. The second time it seems to work