Unfortunately that's not so easy. The processing of the arrays is fairly extensive (runs to hundreds of lines). I had hoped what I'd put might just ring a bell with somone who'd seen similar problems.
The fact that it works with small files but not large ones perplexes me. It may be that I'm running into memory problems I guess. I don't know the inner workings of the Tie code but I suppose if I tie large files I'm ultimately using a lot of memory.