Chosen Solution

sometimes Reportcrash will open and it takes more and more ram until my 3gb of ram is full and the mac runs verry verry slow

Why are you analyzing Crash reports? You should disable it and if you are getting crashes review the crashes on a more powerful system (RAM & storage space) To disable, do this within terminal: launchctl unload -w /System/Library/LaunchAgents/com.apple.ReportCrash.plist sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.ReportCrash.Root.plist