Hello Louise,
Because you've only recently purchased PhD 6, and you didn't have issues previously, I'd have to assume that something was faulty with the installation.
The first thing I'd suggest is a complete uninstall - using a *dedicated uninstaller to remove registry entries - and re-install after a reboot.
*
Revo Uninstaller (the freeware version) is software I've used for this purpose because it does a sound job.
Did you purchase PhD6 outright or was it an upgrade from PhD5? If it was an upgrade, you'd need to re-install PhD5 then repeat the upgrade process.
PIX
PIX YouTube channel