Let’s call it a case of an ebbing tide stranding all boats.

Shares of gambling technology company WMS Industries (NYSE:WMS) were sliding Tuesday, reflecting a weak economy and an even weaker casino economy.

The maker of slot machines and video lottery terminals managed to match Wall Street’s earnings estimates of $0.36 per share, excluding one-time charges, for its first quarter, which ended Sept. 30.  Still, shares were off more than 8% in midafternoon trading.

Revenue of $165 million narrowly missed Wall Street's consensus when the company reported results Monday after markets had closed. WMS said second-quarter revenue would be in the $184 million-$190 million range --just below the average analyst prediction of $194 million.

Fickle investors
WMS’ diverse portfolio of products, services, customers, and locations has made its stock a steadier long-term performer than casino operators like Wynn Resorts (NASDAQ:WYNN) or Las Vegas Sands (NYSE:LVS), which focus on a few markets and which have taken on heavy debt to finance giant luxury projects and expansion plans.

However, WMS couldn’t please investors, even though first-quarter revenue beat the year-ago quarter by 9%, while reported net income rose 26%.

WMS said its second quarter would feature a trifecta of disappointments: lower spending by casinos on new machines, a reluctance by casinos to replace machines as quickly as they did in better times, and the forecast of fewer casino openings versus the year-ago period.

For those seeking the glass-is-half-full approach, WMS says customers are expected to increase their machine-buying budgets early next year. That was good enough for WMS to reaffirm its revenue estimate of $760 million to $780 million for the fiscal year ending June 30.

More fallout
Scientific Games (NASDAQ:SGMS) was another gambling technology company with a diversified portfolio that got whacked Tuesday after issuing results following Monday's market close.

Like WMS, Scientific Games has multiple customers in several continents, although its main focus is lottery tickets and systems. It also provides equipment for racetrack and other sports betting.

Comparative revenue was soft; $239.1 million in the third quarter, versus the Wall Street consensus of $237.9 million. Excluding special items, it posted earnings per share of $0.18, matching the Wall Street forecast.

Scientific Games conceded that 2009 was a "transition" year. "However, now it's simply time to grow," President and COO Michael Chambrello told analysts on Monday. Investors weren't impressed; the stock was down 22% in midday trading Tuesday.

Shares of WMS and Scientific Games were falling while shares of all major casino operators and gambling technology companies were in the red, including several that were diving by more than 10%. It's further proof that even the most diversified business models are vulnerable to an industry beset by uncertainty and volatility.

Fool contributor Robert Steyer doesn't own shares of any companies cited in this story. The Fool has a disclosure policy.