Cannot create a record in Description (TrvPreJourney). The record already exists

Hi

We are using Dynamcis AX 2009.

When in the Enterprise Portal users are getting the error:

Cannot create a record in Description (TrvPreJourney). Expense report number:XXXXXX. The record already exists

We are using a continuous number sequence, which we do not wish to stop using.

When I look on the list of the number sequence it does look like the user has reserved numerous numbers and cleaning fixes the problem.

Any ideas why the users would be encountering this and how to fix it without turning off the continuous number sequence?

Many Thanks

Neil