Hi Carole,
It is a bug, the parameter being passed in from code has a typo @CurentTimeUtc should be @CurrentTimeUtc
I will fix this and put out an update soon.
Note however I'm pretty sure this error will only happen using a debug build of mojoPortal, it will not happen on a production site using a release build (or a release build in VS), sql server is tolerant as long as the expected number and type of params is passed, its the debug assert that raises an exception only in debug mode.
Thanks,
Joe