Apple just made more money than it ever has, but there's one problem

Apple posted $18.4 billion in profit last quarter, its biggest quarterly profit ever, but there's one problem.

iPhone revenue was up a meager 1% and the number of units sold was basically flat year-on-year, resulting in its slowest sales growth since 2007, according to Recode.

It's a sign sales of Apple's golden goose are stalling, and it could spell trouble for the company moving forward.

The iPhone is still Apple's largest revenue driver by a large margin, though, and the company moved 74.8 million units in the holiday quarter (up from 74.4 million in Q1 2015).

iPads aren't faring well, desipite

Its "Other" product category, which includes Apple TV, Apple Watch, Beats products, iPod and Apple-branded and third-party accessories, posted the biggest jump in YoY revenue, up 62% over Q1 2015.

Apple said it had all-time record sales for the iPhone, Apple TV and Apple Watch, though per custom it didn't reveal how many Apple Watches it sold (same goes for Apple TV).

Coming off a huge quarter last year for the iPhone 6 and iPhone 6 Plus, it's not surprising Apple didn't see more growth for what are essentially incremental updates to the phones in the iPhone 6S and 6S Plus.

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