Error log bug (?)

[Elmacik]

Some of the errors refer to non-existing lines in files.
For example it says:

Error:..................
Files:...................
Line: 508

When you go to that file, you see that it contains only 130 lines..
This is usually seen in language file errors. The example above was generated by my old mod.
I added this line to Post.template.php:
include_once("$boarddir./Sources/Upload.php");

It worked but whenever Post.template.php ran, it generated this error:
Undefined index: boarddir
File: Post.turkish.php
Line: 508

I couldnt really understand whats wrong with $boarddir. And why wrong with a language file? (That file consists of only 133 lines)