Negligent technical support advice from TomTom
Never never never never NEVER tell users to turn off their computers firewalls.
You can read my brief dialogue with TomTom's technical support here - yes, I suppose I should have tried switching from wireless to wired before contacting TomTom, but all other downloads from their service were working just fine - it was only maps that were affected, so I was expecting to receive a response indicating high demand on their servers or something like that.
Let's consider TomTom's response logically.
I told them only one download is failing and that I was able to download everything else - therefore we can rule out a problem with antivirus or firewall or router or proxy - if *they* were the problem *all* downloads would fail, not just one.
Obviously their response was no more than a scripted answer sent by somebody who saw 'downloads failing' and didn't pay attention to anything else I said.
So let me repeat...
NEVER NEVER NEVER NEVER NEVER tell users to turn off their firewalls as a troubleshooting step - EVER.