I've seen people have trouble viewing PDFs due to the the limited memory. Oh and I still wonder how many iterations it will take before they realize the benefit of multitasking. On the iPad? It's got atleast 1g memory... On my 3G iphone it was hard to view pdf's sometimes but it's been fine in mine Also old PDF's when it's just images no text don't work so well anywere Really doubt it's due to memory. I'd guess it's more likely programming. I view PDFs every day on my Blackberry Tour, and can't recall ever having a problem loading/viewing one.