Time Warner CFO John Martin told investors yesterday that while online subsidiary AOL's ad network Platform-A "had been growing like a weed,'' the company now doubts it will hit its revenue targets. "We have seen some cancellations," Martin told conferencegoers. "It gives us pause in terms of our confidence to ramp advertising in the back half of the year.'' AOL also laid of 5 to 10 employees from its "Shared Services" group yesterday, SAI reports — the only surprise there being the small size of the cut. AOL's recent efforts to combat waning advertiser and consumer interest in its brand include creating a new huge banner ad format and also allowing AOL.com visitors to access email from other providers.