Bubbles!!!

When I fill a new reservoir it works well for the first 12 hours or so. Then after that time we get a bubble or two which I prime out. After that the reservoir is bubble free until the next change. Even although the reservoir is bubble free at the beginning we always get a bubble after those initial 12 hours. It's routine now for me to fill a reservoir and then check and prime out bubbles 12 hours later. I don't worry too much, now I know to check for them and they're quick and easy enough to get out.

I always get bubbles at 5 hours and 24 hours after a cartridge change. Just do what someone else suggested on here, reprime out the bubbles before they affect me. It only has to be done at 5 hours and 24 hours, and then I can go the rest of the 5 days without worrying.
Some people don't get bubbles, even though my reservoirs are absolutely clear of them before I load, and I keep my insulin at room temperature, as it is all used within 4 weeks, I do still get them, but accept that they are part of my best friend working...

Does your pump have a separate instruction for prming to the cartridge change, if so just detach the tube from the set and do a prime, but make sure that you bang the pump on a works surface until they all come out and travel the whole length of the tube. Then reattach.

I'm not sure how the Medtronic pump works as we use the Animas. With the Animas we disconnect the tubing from the infusion site, take out the cartridge (or reservoir as you call it) and tap the cartridge so that the bubbles go to the neck of the cartridge, push the plunger to get the bubbles into the tubing, then put the cartridge back into the pump. Set the pump to load the cartridge (as you would do when inserting a new cartridge), then onto prime and hold down the prime until all the bubbles are expelled from the tubing. Then reconnect the tubing to the infusion site and that's it all done.

Not sure if you have a help line with your pump that you can phone for help. They would also go over the procedure with you over the phone, if you told them you have a bubble that you want to get out. Sometimes it helps to do things with someone there at the end of the phone, I haven't got your pump else I would offer to do it with you.