I know I'm replying in a topic from 2009
but indeed there seem to be a serious issue with these MDAC updates. KB927779 for MDAC 2.53 installs newer versions of several files than MDAC 2.81.
There are two cases
1) Install MDAC 2.53's KB927779 and then install MDAC 2.81 + MDAC 2.81's KB927779.
After doing so you'll have the following files in the newest version available which comes from MDAC 2.53's KB927779.
odbcji32.dll 4.0.6307.0
odbcjt32.dll 4.0.6307.0
oddbse32.dll 4.0.6307.0
odexl32.dll 4.0.6307.0
odfox32.dll 4.0.6307.0
odpdx32.dll 4.0.6307.0
odtext32.dll 4.0.6307.0
2) Install only MDAC 2.81 + MDAC 2.81's KB927779.
The following files are in their default version as MDAC 2.81 doesn't update them.
odbcji32.dll 4.0.6200.0
odbcjt32.dll 4.0.6200.0
oddbse32.dll 4.0.6200.0
odexl32.dll 4.0.6200.0
odfox32.dll 4.0.6200.0
odpdx32.dll 4.0.6200.0
odtext32.dll 4.0.6200.0
As you can see, in order to have all of the MDAC related files in their newest versions you have to install both MDAC 2.53's KB927779 and MDAC 2.81 + MDAC 2.81's KB927779.
On the other hand, when slipstreaming (HFSLIP) it's impossible to do it as HFSLIP will copy MDAC 2.53 files (other than these listed above) over 2.81's files. I tried to fix this in Update Rollup 2-v2 (which is being tested at the moment) where I did some manual .DLL date modyfing in order to have MDAC 2.81's files copied over the older ones from MDAC 2.53 (UR2-v2 has MDAC 2.53's KB927779 included). After slipstreaming UR2-v2 and MDAC 2.81 + KB927779 for MDAC 2.81 the older 2.53's files will get overwritten but you will still have the newest versions of files listed in 1).
Anyway, be careful when installing MDAC 2.81 as it is true that it can't be uninstalled

the updates for MDAC can be but the installer itself doesn't make backups as far as I see.
This post has been edited by tomasz86: 10 July 2011 - 07:19 PM