[xwiki-devs] unpredictable velocity assignment?

Hello XWiki experts, I'm having a very weird behaviour in a set of velocity files inside curriki, running xwiki 3.5. The view code calls startpage.vm, itself having: #template("xwikivars.vm") which contains: #set($GA_uacct=$xwiki.getXWiki().Param('curriki.system.GA')) and, a few templates later, in analytics.vm, one has: #if("$!GA_uacct" != "0" && "$!GA_uacct" != "") .... <!-- have the setting --> #else .... <!-- missing --> #end I know I could put the #set() statement inside analytics.vm, where it was some versions ago. However, I'd like to understand. What I have as behavior is that about half of the executions above show missing and the other half doesn't have them... - should I never expect this variable to be defined inside analytics.vm? (there would be other settings such as the hostname that are needed and are read the same fashion) - shouldn't this variable always be defined? thanks for hints. Paul