AOL

(AOL)

was down 7.2% at midday after opening higher. The company beat the Street's third-quarter earnings estimates and offered a generally upbeat outlook, but some analysts were cautious.

Merrill Lynch's

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Henry Blodget said the company is feeling the effects of the dot-com shakeout and for the "first time in years" he could not raise earnings estimates.

Lehman Brothers'

Holly Becker said the company's flat ad backlog raises questions about the future of online advertising and its effect on AOL.

Credit Suisse First Boston

, however, reiterated its buy rating and 12-month target of $80.