<p>Enthusiasm over Research In Motion Ltd.'s better-than-expected second quarter results cooled somewhat Friday as investors took stock of the challenges that continue to face the BlackBerry maker.</p><p>"Nothing in our thesis has changed," TD Security analysts said in a note to clients. "We are still concerned that the device business is running negative gross margins."</p><p>And while the quarterly results reflect strong international subscriber growth and effective cost management, Oppenheimer Research noted shipments of RIM's BlackBerry smartphones continue to slide overall, especially in the key U.S. market.</p><p>"We expect the business to bleed over time with losses to Apple's iPhone and a stronger Android ecosystem.</p><p><a href="http://www.thestar.com/business/article/1263671--rim-stock-jumps-after-results-were-better-than-expected">Keep reading...</a></p><p>Read also:</p><p><a href="http://www.zdnet.com/blackberrys-tech-appeal-dev-friendly-rim-bets-on-tools-and-openness-7000004968/">BlackBerry&#039;s tech appeal: Dev-friendly RIM bets on tools and openness</a> (ZDNet)</p><p><a href="http://abcnews.go.com/Technology/rim-blackberry-10-make-outdated-focus-keyboard/story?id=17349099">RIM: BlackBerry 10 Will Make Others Look Old</a> (ABC News)</p><p><a href="http://news.cnet.com/8301-1035_3-57522018-94/blackberry-10-how-rim-might-reel-you-in-really/">BlackBerry 10: How RIM might reel you in. Really</a> (CNET)</p><p>Explore: <a href="http://news.google.com/news/more?pz=1&ned=us&ncl=dpWmNh91pdeKA5M65EEpyQYKW3iwM">2,302 additional articles.</a></p>