Citrix ( CTXS) said second-quarter earnings rose 64% from a year ago, paced by strong North American sales growth. But Citrix's shares, which were up nearly 60% at one point this year, tanked after hours as its guidance failed to inspire bulls. Citrix earned $46.5 million, or 24 cents a share, in the quarter, compared with $27.9 million, or 16 cents a share, a year ago. Excluding items including amortization and stock options expense, Citrix earned 33 cents a share in the latest quarter, matching the Thomson First Call consensus. Second quarter revenue rose 30% to $275 million, beating the consensus estimate by about $9 million. By region, Americas revenue rose 36%, while Europe-Middle East-Africa revenue rose 20% and Pacific rose 24%. The company's product license revenue rose 28% in the latest quarter. "We saw across-the-board strength in our product portfolio and in our geographic segments," the company said. "We are well positioned for the second half of 2006 as we continue to drive our access infrastructure strategy." For the third quarter, Citrix expects to earn 33 cents or 34 cents a share, excluding items, on sales of $275 million to $280 million. Analysts were forecasting earnings of 34 cents a share on sales of $272.9 million. For the year, Citrix sees earnings of $1.36 to $1.39 a share, excluding items, on sales of $1.11 billion to $1.12 billion. Analysts were looking for earnings of $1.38 a share on sales of $1.1 billion. Citrix closed regular trading Wednesday at $34.77, down 0.6% on the day but up 21% from the start of the year. In after-hours trading, the shares skidded $4.17, or 12%, to $30.60.