The administration is not pushing any such line, I don't think. Those that do push it somewhat, like Newsmax and the World Tribune, are pretty consistent with implying Russia and Syria are the conspirators who moved the stuff into the Bekaa Valley. The only fill-in-the-blank favorite theory option is why they moved them.
I like this:
The arming of Iraq with such weapons has a direct impact on events today in the Middle East. The presence of former Iraqi WMD systems in Lebanon raises serious questions surrounding the Feb. 14 assassination of former Prime Minister Rafik Hariri. Many blame Syria for Hariri's murder.
However, the possibility that Hariri discovered the location of the Iraqi WMD systems inside his country lends some credible backing to a Syrian assassination effort to silence him.
In addition, the sudden sale of advanced missile and other weapons to Damascus by Moscow also supports the allegation that Syria is hiding something for Russia.
I didn't mean to imply that I thought they were pushing it, I was saying one of the reasons you're not hearing more speculation from the administration is because it doesn't play well with people when you have a new explanation of what may have happened to the WMD every other week.