That doesn't sound right. My X350 mulch kit came with different blades -- the dealer gave the original blades back to me. Any blades will "work" but a mulching blade provides lift to allow time for more cuts, meaning smaller pieces. You should talk with a dealer, not a reseller....Before I purchased I was shopping around and I noticed most mulching kits for other mowers came with a different blade. But the kit they recommend for this mower (42-in mulch kit (228462)) is only a plastic cover. Is that really all I need to make this a mulching mower? The same blade it came with is fine for mulching?