Line chart doesn't drawo latest value point

I have been keeping share price records for my investment club running since 1996. Any shareholding running for any length of time doesn't show the latest date and value when I put my mouse on the end of the line, but I can take my mouse on further than the line is drawn and I am able to read the appropriate data from the empty space. I am using Excel 2010 on a 64 bit windows 8 computer. Previously I was using Excel 97/2003 on an XP computer and din't seem to see this problem.
It's weird! Any ideas?

Hasn't anyone else experienced this? I have consulted with others who've had ideas but no solution. I've gone through multiple versions of "Select data" and put in false extreme data that does seem to be properly represented, but on the genuine data the line is always out of date. Is it possible to have Office 2003 in parallel in my machine?