Symantec 12.1 LiveUpdate incorrectly reports low disk space

I've got 23GB free on this laptop and Symantec EndPoint Protection Small Business 12.1 keeps insisting I need to run disk cleanup to free some disk space.

I found this recent Symantec post that talked about proxies causing that problem
http://www.symantec.com/docs/TECH157197
but I don't think that applied on this site

I then found this old (!) 2008 post talking about the same problem with Symantec EndPoint 11.02 and how to fix it by removing the check from the registry
http://www.symantec.com/connect/forums/live-update-low-disk-space
except I couldn't find that value in my registry.

I did work it out in the end, I'm on 64 bit Windows 7. The equivalent location to check in the registry is
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run
where I found the entry for ALUAlert and deleted it :-)

I did also note that in the Control Panel under Symantec LiveUpdate Settings > Update Cache, the max cache size was only 10MB so I bumped that up to 100MB.

Only thing is I don't know which fixed it now :-(