Oscar question problem

[Lanco]

Just switched to my backup Resmed S9 as I was having some problems with the old one.  I read the data from my old S9 just to see what was going on and then used the card for my new S9 in oscar.  I decided to reformat the card for the new one which my cpap said it did.  I thought I would check it to make sure it was blank.  It still shows the data for the few days I've used it and other data going back some time.  Not sure if it somehow is mixing in the data from my older machine or what.  Also, I used to use the backup S9 to dry our hoses twice a month for a total of about six hours a month.  Also wanted to ensure the unit was operating ok as when I first got it it was used with 100-200 hours on it and it ran hot when I first tested it out.  After that it never seemed to run hot and wanted to keep it in top shape.

What's going on here.  I'm thinking my new SD card should be blank so I can start fresh so my averages are accurate.

Thanx

Scott