I believe so. I have many DVD rips that are under 4gb and play fine. I have one over 4gb that will not play. If I re-rip the same DVD to a quality which is less than 4 gb it plays fine.
Resolution is correct and the ripper is compatible. Having used it many times at the highest conversion quality there has never been a problem.
I've been able to replicate this issue with other longer videos that exceed 4gb.
Looks like its the native video iPad video player. I downloaded a third party app called Media Player and after linking to my network drive all videos over 4gb that won't stream using the native video app work fine with Media Player.