CDJ-2000NXS emergency loop and "now loading" issue

Hello.

The problem is when iam playing via recordbox link i get random emergency loops or a very long "now loading" (while loading some track) this happens completely random with random tracks. Sometimes it is2 times per hour with 2 decks the same sometimes just one deck, sometimes it happenes ten times per  hour, sometimes it doesnt happen in an one hour time etc. After a few senonds the "reloop/exit" button starts to blink and i can exit this emergency loop. My configuration: Windows 8.1 intel core i5 notebook "lenovo", 4gb ram, 750gb hd, 2xcdj2000nexus fw 1.21, 1xdjm900nexus fw 1.30 connected each via cat 5e lan cables to TP-LINK TL-SF1005D ( http://www.tp-link.com/en/products/details/?categoryid=&model=TL-SF1005D ) + to one free port connected via cat5e lan cable a Wireless TP-LINK TL-WR720N router ( http://www.tp-link.com/en/products/details/?categoryid=&model=TL-WR720N) not used in this issue.