G'day mkalas,

Welcome to the monastery.

While the order of declarations may be a factor, the scope of the declarations will typically be more important. Furthermore, the order in which code appears may not necessarily be the same order in which it is compiled.

You'll need to show the code where %LOG_FILE_HASH appears. It may be scoped to the subroutine: in this case, it will be a completely different %LOG_FILE_HASH to the one referenced by $LOG_FILE_HASH{$FILE}; alternatively, it may be exactly the same variable.

There's far too many possibilities to try and guess what you might have and then to describe each one: post your code (in <code>...</code> tags, as LanX has already pointed out) and a definitive answer can be provided.

Here's some general reading that mostly covers this topic: sub; perlsub; use; perlmod: BEGIN, UNITCHECK, CHECK, INIT and END. I expect that will be rather heavy going: with a better idea of your code, a simplified explanation can be provided.