I am also suffering from duplicate records, This is the third time it has happened to me. I believe there is a recently introduced bug in the weather link Software, I have now upgraded to 5.8.2.
The last time I had the bug I was using 5.8.1, I can't say before that as I was not taking notes.
I think what is happening is that if for some reason the software is interrupted, it appears to get its counts of where its up to in the database out of step.
Having once got out of step, each day it gets a further record count out of step.
I have reported this to Davis in the past but the help desk was very unhelpful
, which seems to be a recent backwards step as they were always really on the ball.
You notice the feature (bug) has occurred because you start getting strangle lines appearing on graphs produced for the internet.
First thing to do is to export your data to a text file, for safe keeping. Then restart the software.
The fix is to manually browser the records and delete the extra records. You will then notice the pattern of extra records one the first day, two the next, etc.
Do not get carried away deleting things, as I have and delete too many records, if you do use http://www.ruysfamily.com/WLKReaderWriter/WLKAppDownload.html
to get out of that mess, and look at the text file you took earlier for the data, to put back in.
Cheers Ian Mac