Re: BT Business Hub and Mountain Lion download...
It would seem that if you can get past 110Mb downloaded, the rest will carry on... Here's how I downloaded ML from the Mac App Store in less than 30 mins...
1. Using the regular BT connection, start the download
2. Checking in Launchpad (for speed) you will see the download sticks at 50-100Mb
3. When it sticks, pause it (click the icon once in Launchpad)
4. Download and install Hotspot Shield, let it do it's thing until it says you're 'protected'
5. Continue your download of ML (Launchpad, click the 'paused' Mountain Lion icon so it resumes)
6. The download should start to continue... you may need to 'pause/unpause' it a couple of times.
7. All sorted, installable and glitch-free for me.
The problem, as discussed, is the maximum download size for a single file from BT Business hubs.
You can uninstall the Hotspot Shield from the .dmg once it's been used.