Is this a bug?

If I use this nomenclature online, the script won’t run.

putnpc firerodicon.png,#a#s(client.resetnumber)_visited.txt,30,30;

However if I use this one:

putnpc firerodicon.png,#a#s(client.resetnumber).txt,30,30;
the script runs.

Seems like a filename length problem, should I bug it?

EDIT:
But if I do this:

  setstring client.visitedfile,#a#s(client.resetnumber)_visited.txt;
  putnpc firerodicon.png,#s(client.visitedfile),30,30;

it works… O_o

But it still seems to have a filename length limit…