The options to copy/paste/add comment are not appearing when I select a cell, any idea what I have done?

Question

I was working on a spreadsheet, adding comments (yellow comment area), then I decided to see what these arrows do (< > ) I can see they are used for skipping through the comments. But now when I try to add another comment, the option doesn't appear, as well as when I select a cell, the options to delete, copy, cut, paste, etc. do not appear either...
Does anyone know what I've done and how to fix it?!

Answer 1

You may have a malware infection.
Do a malware check with a few malware scan programs.<br />
You need to use all programs because each detects different malware.<br />
Make sure that you update each program to get the latest version of the database.
*http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
*http://www.superantispyware.com/ - SuperAntispyware
*http://www.safer-networking.org/en/index.html - Spybot Search & Destroy
*http://www.lavasoft.com/products/ad_aware_free.php - Ad-Aware Free
*http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
See also "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked and [[Searches are redirected to another site]]
If you can't fix it with the above listed scanners then you need to ask advise on one of the forums that specialize in malware removal mentioned in the <i>Popups_not_blocked</i> article.