The Vodafone 845 is using the same ZeroCD crap as other UMTS hardware by Huawei. For Linux (or libusb), usb_modeswitch exists, but this did not work for me.
So here is how to toggle the device itself without any special driver.
su -c ‘echo 1035 > /sys/devices/platform/msm_hsusb_periphera/composition’
This will not hide the Mobile Partner CD drive but its USB product id changes, which allows now to use the osx-pl2303 driver and also adb from the android SDK to be used.
See here for how to load the pl2303 driver. Note that OS X is using decimal representation of vendor id and product id (0x12d1 -> 4817, 0x1035 -> 4149).
This should also work with the T-Mobile Pulse Mini and maybe with other Android devices built by Huawei.
Edit: You need to have root on your device.
If you have root, you can try this small application: ToggleUSB.apk
Google hints: Vodafone 845 u8120 0x12d1 0x1031 0x12d1 0x1035 Mobile Partner Pulse Mini