I have replied by email but for others I am also replying here.
Having looked at the Sailwave file you sent me and it together with information in this email, has allowed me I think to determine the issue. The key bits of information in this email were
* original file you entered scoring codes before actual finishes
There are indeed two competitors with recorded finished of 1st in R5&6, but to see this for Sailno 1699 you have to use Edit result. Your RDG code has the method “Average of all races not DNC”. I am not sure how you entered the information for R5&6 for SailNo 1699 but my guess is you somehow entered a finish position of 1st and then changed it to the code RDG.
Sailwave for some reason, which Jon will have to look at, when it comes to scoring, picks up that there are 2 recorded places of 1st and averages them hence the 1.5 scored points for SailNo 2523 in R5 and SailNo 1525 in R6. I manually changed the recorded places in R5&6 for SailNo 1699 to 999 and the set back to code RDG and then scoring worked as expected.
There is another little anomaly in Sailwave that if you do not have a recorded result for a competitor when using a scoring method that averages a range of scored point, things go awry in scoring as well. I found this out when a competitor did not finish a race asked for redress and was awarded RDGa.
Hope that all makes sense.