iMac EFI Firmware Update (Version 1.8)

I keep on getting repeated requests to update the EFI Firmware every few days or so on the following dates:

Oct 7, Oct 9, Oct 14, Oct 15, 2014. The updates were succesfully installed, and yet I get the instruction to update again and again. What went wrong?

(I'm using a 27-inch iMac, mid 2010 model)

Remove the updater (in /Applications/Utilities, I think). Download and reinstall it: iMac EFI Update 1.8

If that doesn't sort things out, you might try resetting the SMC: Intel-based Macs: Resetting the System Management Controller (SMC)