Acceleration: installation aborted

Hello,I've done a search about this topic, but so far I couldn't find any clear results, so I'm posting a new thread about it.Everytime I try to install Acceleration, I'm getting the following error message at the end of the installation, right after the DirectX update performed by the installer:'An error has occurred during the installation of assembly 'Microsoft.FlightSimulator.SimConnect,version="10.0.61259.0",publicKeyToken="67c7c14424d61b5b",processorArchitecture="x86",type="win32".'Initially, I tried to install over a working installation of FSX-SP1, and this error showed up. Then, I proceeded to uninstall all add-ons and FSX itself, then re-install FSX again. With a brand-new FSX installation (RTM), I tried Acceleration again, but the installation aborts at the same point with the same error message stated above. Then, it reverts FSX back to its previous state.Also, if I try to install the new SDK, I get a similar error:'An error has occurred during the installation of assembly 'Microsoft.VC80.OpenMP,type="win32",version="8.0.50727.42",publicKeyToken="1fc8b3b9a1e18e3b",proccessorArchitecture="x86".The OS is Vista Ultimate 64, with all security KBs, .NET and all that stuff up-to-date. I'm using an administrator account. UAC is disabled, as well as BitDefender and anti-virus (just in case).I've spent all day trying to get this thing installed. Any ideas?Orle