Predicting mobile computing sales is a tough one, especially when rolling out a relatively new product. Unless the production numbers match sales expectations perfectly, investors are going to be disappointed. Just ask Apple (AAPL -1.22%).

On Monday, Apple cut orders from its iPhone 5 manufacturers by as much as half due to lack of demand. Forget that production changes often occur after the busy holiday shopping season, or that Apple could have previously placed massive orders to adjust supply chain problems with its new iPhone, or any other fair reason. Investors weren't interested. Apple stock proceeded to drop over 3%, and remains below $500 a share.

Google (GOOGL -1.23%) and its Nexus 4 smartphone partner LG have found themselves in a similar situation as Apple, though on the opposite end of the spectrum. The problem for Google is too much demand internationally for its low-cost smartphone. It took all of 20 minutes for Google's Play store to sell out of what was then its new Nexus 4 for the international market, and the backlog of orders isn't improving.

He said, she said
In response to concerns about production keeping up with Nexus 4 demand, a director in Google's U.K. offices said, "Supplies with the manufacturer [LG] are erratic," not exactly a glowing recommendation for LG. One estimate put the number of Google Nexus 4 sales since its release a couple of months ago at 370,000; not bad, but paltry compared to Apple and Samsung numbers. So, when in doubt, apparently you blame the supplier.

However, LG isn't taking Google's insinuations about production problems lying down. In a recent interview, an LG executive pulled no punches when asked what the problems were in keeping Nexus 4 phones in stock. According to the LG exec, Google underestimated demand, particularly in the U.K. and Germany, by as much as 10 times the number of Nexus 4's needed to fill orders.

The price for being wrong
The impact of its Nexus 4 supply issues on Google's bottom line will be negligible when it announces earnings Jan. 22. The Nexus is, after all, relatively new to market and Google certainly has other sources of revenue. But Google's inability to meet demand will hurt its share price in the near term, but will be little more than a hiccup in the overall scheme of things.

The flip side of Google's production issue is Apple. According to estimates, Apple sold around 50 million smartphones in the recently completed Q4 of 2012. But because of declining sales expectations this quarter, Apple cut component deliveries and its share price got beaten down. Can you imagine if Apple planned for 40 million units, and were then forced to announce a ramp-up in production to meet demand for 10 more million iPhones? You can bet share prices would have soared.

Is it any wonder Microsoft (MSFT -1.27%) hasn't released sales data for its Surface tablet, or why it was initially rolled out on such a minimal basis, with temporary retail outlets? If Microsoft CEO Steve Ballmer had shot for the moon relative to Surface sales, and didn't meet those lofty expectations, he'd feel the wrath of shareholders all the way up in Redmond, Wa. Of course, if Ballmer undershot expectations, and then was having production difficulty filling orders, shareholders would again be on the warpath.

When it's said and done, supply and demand forecasting isn't an exact science. Sure, there's information that can be gleaned from changes in orders and amounts, but let's keep it in perspective. Do Google's issues with LG threaten to derail the online leader? Of course not. Take the 4% drop in Google's share price the past week for what it is: an opportunity.