Merrill Lynch & Co blames manufacturing glitches and logistics issues for a shortfall in sales of Silicon Graphics Inc’s new Windows NT workstations which lead to a shortfall of up to $30m on the original target of $75m to $100m in sales in the quarter. Low yields of the new Cobalt graphics processor take the brunt of the blame. The delay shipping the new 350-MHz MIPS R12000 CPU and sales force transition didn’t help, it says. Volume shipments are now expected in the September quarter. It estimates revenues will be between $600m and $650m, down from an original estimate of $733m.