After we updated Flash to version 13.0.0.182 with SCUP/SCCM it stopped working on ~5% of the computers, reinstalling it fixes the problem but a new version of Flash which doesn't cause the same problem would be the prefered solution.
Opening https://www.adobe.com/software/flash/about with IE gives the following screen:

Installation log from an affected machine:
=X====== M/13.0.0.182 2014-04-09+08-54-14.392 ========
=O====== M/12.0.0.77 2014-04-09+08-54-16.454 ========
0000 00000010 C:\WINDOWS\system32\Macromed\Flash\FlashUtil32_12_0_0_77_ActiveX.exe -uninstall activex -msi
0001 00001037 SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Adobe Flash Player ActiveX/ 2
0002 00001037 Software\Microsoft\Windows\CurrentVersion\RunOnce/FlashPlayerUpdate 2
0003 00001037 Software\Macromedia\FlashPlayerActiveX/ 2
0004 00001037 Software\Macromedia\FlashPlayer/SwfInstall 2
0005 00001037 Software\Microsoft\Code Store Database\Distribution Units\{D27CDB6E-AE6D-11CF-96B8-444553540000}/ 2
0006 00001021
0007 00001036 Software\Macromedia\FlashPlayerActiveX/PlayerPath 2
0008 00001036 Software\Macromedia\FlashPlayerPlugin/PlayerPath 2
0009 00001036 Software\Macromedia\FlashPlayerActiveX/PlayerPath 2
0010 00001036 Software\Macromedia\FlashPlayerPlugin/PlayerPath 2
0011 00001037 Software\Microsoft\Windows\CurrentVersion\Control Panel\Extended Properties\System.ControlPanel.Category/C:\WINDOWS\system32\FlashPlayerCPLApp.cpl 2
0012 00001036 Software\Macromedia\FlashPlayerActiveX/PlayerPath 2
0013 00001036 Software\Macromedia\FlashPlayerPlugin/PlayerPath 2
0014 00000012
=X====== M/12.0.0.77 2014-04-09+08-54-17.164 ========