From what I can tell, the MC75A launched in March 2010.  The then-current release of MSP was MSP 3.3, which was released in October 2009. As each new version of MSP is released, we test and certify that it supports all released MCD devices, hence MSP 3.3 would have been tested and certified for the then-current BSP for the MC75A.  As a general rule, we do not, and cannot test every prior BSP for every device. As each new device or BSP is released, the device team tests that new device or BSP and certifies it for use with the then-current release of MSP.  As a general rule, the device does not, and cannot, test against every prior version of MSP. So, at its launch, the MC75A would have been tested and certified for use with MSP 3.3.  The MC75A would NOT have been tested or certified for use with MSP 3.2 (released in 2008) or MSP 3.2.1 (released in March 2009). That does not mean that MSP 3.2 DOES NOT WORK with the MC75A.  But it does mean that it is an officially unsupported configuration and any use of a prior version of MSP with the MC75A cannot be supported.  To use the MC75A with support, the customer would need to be using MSP 3.3, at a minimum.  Of course, Motorola Solutions ALWAYS recommends that customers use the most recent version of MSP and the most recent BSP for every device.  Also note that fixes and updates to MSP are ONLY provided through NEW releases, hence the only avenue available to a customer desiring a fix or an enhancement is to upgrade to a new version of MSP.