Malicious Software Removal Tool updates not working properly

I am having a problem with the MALICIOUS SOFTWARE REMOVAL TOOL updates
I successfully downloaded and installed the MSRT updates through FEB 06.
But I have had a problem with the March and April 06 updates. I have
automatic updates set up, but I keep getting a "!" bubble on the lower
right-hand taskbar which says that updates are ready to be installed. I click
on "install" and the window then says that the update had downloaded and been
installed. But then 30 seconds later the "!" bubble reappears with the same
message telling me that updates are ready to be installed. I click on it
again, and again it says that the update was installed. But then the "!"
reappears, and so on, and so on.
I went to the microsoft website and tried to download the MSRT' there, but
the same problem occurs. I checked my "update history" and it shows that the
updates have been successfully installed many, many times (the green
checkmark).
But then someone told me to click "start/run" on my taskbar and then:
%windir%\debug\mrt.log
That log shows every MSRT update through FEB 06 as installed with no
infection.
But the MARCH and APRIL updates do NOT appear on the log! The log ends with
the FEB 06 info. I have scanned my computer for virus and spyware from
multiple sources and all come out clear. PLEASE HELP!! Why aren't the
updates installing properly?
Thanks for any help! I am ready to pull my hair out!
Ski