I am confused and therefore I simply tried it.

#!/perl

open( FILE, ">", "this is a test . txt" );
print FILE "yeah";
close( FILE );

open( FILE, "<", "this is a test . txt" );
while (my $line = <FILE>)
{
    print $line;
}
close( FILE );
[download]

Works out fine and prints the expected yeah. I am working on win32 with Activeperl. What are you working on? And I even went further and made a

#!/perl

mkdir( "another test" );

open( FILE, ">", "another test/this is a test . txt" );
print FILE "yes, yeah";
close( FILE );

open( FILE, "<", "another test/this is a test . txt" );
while (my $line = <FILE>)
{
    print $line;
}
close( FILE );
[download]

giving me the yes, yeah. What is your exact problem?