A recent downgrade of VeriSign ( VRSN) based on poor performance from its ring tone division seems to signal that the trendy sector is clamming up faster than expected. But not according to industry analysts, who remain bullish on the phenomenon that centers on teens' interest in personalizing phones with song snippets and other novelty sounds. While cell phone carriers such as Verizon Wireless -- a joint venture between Verizon ( VZ) and Vodafone ( VOD) -- and Sprint Nextel ( S) are still reaping the spoils of the ring tone fad, the stand-alone sites -- such as VeriSign's Jamba/Jamster --- have perhaps neared the top of their growth potential, and as a result, the company is hitting a sour note with some analysts. "Dropping Jamba/Jamster would boost the company's fortunes. No matter what the means (divestiture, spinout, shutdown, etc.), we believe getting out of the ring tone business would be a positive move and we would reconsider our stock opinion," wrote American Technology Research analyst Albert Lin in a recent note. "Boot Jamba/Jamster or boot the stock is our bottom-line assessment." American Technology Research does not have a financial relationship with VeriSign. Lin downgraded VeriSign from hold to sell, and the stock slipped 3.8% on Monday and Tuesday before closing up by 15 cents to $23.81 on Wednesday. Vernon Irvin, head of VeriSign's communications services unit, sees ring tones as part of a much larger mobile media market as more users flock to features such as video ring tones and song downloads and says the company has "not engaged in any discussions" to sell the unit, which it acquired in 2004. But other analysts have expressed reservations about Jamba/Jamster's prospects. In a Wednesday research note, Jeffries & Company analyst Katherine Egbert rated the company hold with a $24 price target because of the "uncertainty around Jamba. It is difficult to know how fast or how far this business declines in 2006."