App Store: download mountain lion calculating never stops

Question

Just purchased mountian Lion, it gets to about 74mb and then does a calculate on download time, but never returns, the download never continues... any ideas why?

Answer 1

It appears that if you are using a 2-Wire router from BT that it will stop after between 50 and 80Mb. This seems to be down to some kludge BT have put in to stop large downloads. I've found three workarounds for this - one is to contact BT and give them the serial number of your router and they can send a firmware patch. This doesn't help over the holidays of course. Another option is to enable OpenZone on the router, disconnect ethernet and connect to the OpenZone wireless - this is what eventually worked for me although initially App Store wouldn't connect via OpenZone (left it for a while and Mountain Lion was halfway done). A third way is to connect the laptop directly to the router in bridged mode with a PPPoE connection. Not for the faint hearted:
Disclaimer: Please do not attempt this if you do not know what you are doing. You will need to factory reset the router when finished so please ensure you have a note of all settings before proceeding. Also it's sensible to make sure the Mac's software firewall is on before doing this.
1. Set up an ethernet connection between the Mac and router. Test and make sure it works!
2. In the Mac network settings, create a new PPPoE connection. Enter your BT Broadband network login details
3. Log into the router interface and go to Settings > Broadband > Link configuration
4. Set ATM-Encapsulation to Bridged LLC
5. Untick the ATM PVC search box
6. Set Connection type to Direct IP
7. Scroll down and click save
8. Untick the enable routing box
9. Click the save button again
10. Go back to the Mac network settings and click connect on the PPPoE connection.
You should now have a connection which will allow you to bypass the file size limitation of the router. When you are finished, you will need to factory reset the router and reconfigure it as before. You can also delete the PPPoE connection.