Frontpage module, perhaps K2 image load problem

Hello, i'm not sure if this is a K2 problem or has something to do with the gavick modules.
I always have this problem with the myfolio template. When i try to renew the images for the homepage (the images you see at the very first page with the "Launch project" hover) which were set in the k2 articles/items under the image tab. I always have to load it, don't know, 30,50, 70 times until it appears on the frontpage. I tried everything from deleting the cache from the browser, the joomla cache, tried it to upload from the server or within the upload file button, check the button "delete" the old image or not, but can't find the reason for the problem. Has somebody the same problem and perhaps a new hint for me?
Thank you Markus

Hi

Please show me Your site and tell me if it's only the image which is not showing or the whole K2 item is missing for some time before upload ?