Philippe Dauman Viacom CEO (R) with rapper/mogul Sean Combs

As Viacom Chief Executive Philippe Dauman was managing investors expectations speaking downtown at the Goldman Sachs Communicopia conference, back at  its midtown Times Square HQ, staffers at flagship unit MTV Networks were fretting as pink slips were being handed out. There was widespread concern internally, according to a source. (AdWeek reported it last night).

Dauman was his usual deadpan self as he lowered outlook, saying advertising sales would still be up but by “high single digits” percentage growth rather than the double digits growth he had promised as recently the third quarter call just last month.

Viacom shares tanked by some 9 percent on Thursday, more than a wider market downturn, as investors read Dauman’s cutback as an early sign of worse to come. The worry on everyone’s minds is of another major 2008-like ad recession may be round the corner. Shares are off another 3  percent on Friday morning.  It’s worth noting CBS, whose revenue is 70 percent advertising, dropped by 7 percent despite bullish comments by CEO Les Moonves a day earlier. It shows how jumpy everyone is right now.

But in fact Dauman explained that the cut back was due to a short-term programming ratings issue rather than economic headwinds.

Here’s Nomura analyst Michael Nathanson said he had “unpleasant flashbacks to May 2008″ when Viacom lowered advertising guidance during a Q&A he had Dauman. However, there are a number of key differences.” He says Viacom has less debt load than 2008, it’s trading at a lower valuation than in 2008 and he feels it will benefit from ongoing profit margin expansion at its international business.