So I have a VPN setup on a customers UC560 that has been working just fine for close to a year. The 525 phone worked well at a remote location for 6 months and has been nothing but problems since.
I have wiped it to factory defaults, updated the firmware to 7.5.5, re-configured it via the wizard in CCA, increased the VPN DHCP pool to 10 from 3, and it tests out fine on our shop network here at work. After that it is 50/50 whether it wants to sync up and work properly off-site. The client brings it to his house where he has cable internet and a basic Linksys router and it boots up, shows the VPN icon on the top bar as connected but just sits at downloading some .xml file. Bypasses the router and same thing so it can't be a weird firewall issue.
I was under the impression that if this phone finds an internet connection it would work. Don't understand all the hit and miss whether it's going to sync up or not.