Considering that 5.46 was released over four years ago
, you really do need to upgrade, yes. <img src="https://www.ubbcentral.com/boards/images/graemlins/wink.gif" alt="" />
I'd suggest downloading the trial version (link's on the left) and installing it on your server - if it installs without a problem (no mysterious and annoying internal server errors), then you'll have no problems upgrading either. It's a trimmed down version of 6.6, the previous major version.