Cablevision Systems Corp.'s nasty slide — $8.51, or almost 21 percent, between Feb. 11 and Feb. 20 — may have ended last Thursday. Aided by Morgan Stanley's upgrade of fellow MSO Cox Communications Inc. (see Tip Sheet), Cablevision ticked up on Thursday morning. Investors may have also been listening to other analysts, who put out reports like the one by Salomon Smith Barney's Niraj Gupta, under the headline "We Believe Cable Weakness Is Becoming Exaggerated." Cablevision typifies some investor concerns, suffering through digital-service technical problems and acknowledging that it might need funding in 2003. But Gupta noted that Cablevision could fill its funding gap by selling non-core assets.