<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Laurie,<div class="">We have seen this as well, but not often enough for us to get figure out what is going… My guess is that it has something to do with the video card, but it is only a guess… You might try and update the drivers on your video cards (see this link for more information: <a href="http://alice3.pbworks.com/w/page/54959364/Updating%20Video%20Drivers" class="">http://alice3.pbworks.com/w/page/54959364/Updating%20Video%20Drivers</a>). And it is true that restarting Alice tends to resolve the problem, but it certainly is irritating.</div><div class=""><br class=""></div><div class="">Have you noticed if it is the same machine or set of machines in your lab?</div><div class=""><br class=""></div><div class="">Thank you,</div><div class="">Don Slater</div><div class=""><br class=""></div><div class=""> <br class=""><div><blockquote type="cite" class=""><div class="">On Dec 11, 2014, at 9:57 PM, Laurie Solomon Cohen <<a href="mailto:lscohen613@aol.com" class="">lscohen613@aol.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><font size="2" face="Tahoma, Arial, Helvetica, sans-serif" class="">Is there a reason why sometimes the screen will turn black? It seems for no reason. Most times if the student just shuts it down and then reopens Alice (we're using 2.4.2), it is fine.
<div class="">Are we doing something that causes this?<br class="">
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<div style="clear:both" class=""><i style="background-color: rgb(255, 255, 255);" class=""><span class="Apple-style-span" style="font-style: normal; font-family: 'Times New Roman', Times, serif;">
<div style="font-size: 12px; clear: both;" class=""><font face="Comic Sans MS, sans-serif" size="2" class=""><i class=""><span style="font-style: normal; font-family: arial;" class=""><b class=""><i class="">Laurie Cohen<br class="">
Yeshiva of Greater Washington</i></b></span></i></font></div>
<div style="font-size: 12px; clear: both;" class=""><font face="Comic Sans MS, sans-serif" size="2" class=""><i class=""><span style="font-style: normal; font-family: arial;" class=""><b class=""><i class="">Silver Spring, Maryland</i></b></span></i></font></div>
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