I ran into this problem as well. Was fine until Chrome 32.0.1700.76. It seems to be related to the bsnAutoSuggest_2.1.3 mod I added from Timothy Groves. This mod pulls user's info from LDAP and suggests names as you start typing in the name field for creating a new ticket. When you select one, it then populates the name location and phone fields for you. I was able to stop the pop up by commenting out a line in the ajax.js file (in my case located at {ost}/scp/js/ajax.js). The line I commented out was line 47, which said " Http.enabled = (Http.req != null); "
I know squat about javascript, so I can't speak to why this caused the error or why commenting out this line stopped the error yet the auto-suggest function continues to work fine. Perhaps someone else with more skill can take a look and shed some more light. Anyway, just wanted to contribute what I'd found. I guess it is time to buckle down and stand up a test instance of the newest version and start working on porting all my mods over (sigh).
Wooow!!! nice catch in all that code! I also commented out that line and the popup is no longer shown