I've gotten several MMS from others since the update, including two today. I'm betting it's not CSSU causing it directly. It could be that your service vendor has put something in place to detect your IMEI and is now not sending you MMS because the phone officially (as launched) didn't support it. There were several operators that had to be educated to fix this when fMMS first came out.

If you can send MMS, but not receive them, I'd suspect the operator more than anything on the device.