Clicking on Open Vault brings up box "New Vault Creation"

Every 5th-6th time I try to open my vault, a box pops up for me to Create a new vault and asks to create a strong password. It also warns that doing so will erase any thing already in my vault.After many tries  at logging on,I usually have to reboot to get the vault open...then it will work for a couple of days.

Windows 7 Home Premium, Norton Security