DIAGNOSIS New unit smell or taste transfer from the internal plastic components and lines. It's common and fixable.
FIX Do NOT use the ice from the first several cycles. Perform the self-cleaning cycle (hold Power + Select for 3 secs), then let the unit make and discard at least 3-4 full batches of ice. Use only filtered or bottled water for this initial seasoning process.
IF THAT DIDN'T WORK Check your water source. Highly chlorinated tap water or water run through a softener can impart taste. Switch to a different filtered water.
HEADS UP Never add anything scented (like lemon juice) to the water reservoir to try to freshen it—it will coat the system and make the problem worse.