An extraneous character was my thought also, with the usual suspect being a newline, the data being read from a file (but in that case, the regex must be modified with  /s so that "dot matches all"), or perhaps some kind of "end-of-text" character. Did you do a hex dump of the file yet?

>perl -wMstrict -le
"my $s = qq{pl\n};
 ;;
 print 'match sans /s' if $s =~ /p.{2,6}/;
 print 'match with /s' if $s =~ /p.{2,6}/s;
"
match with /s
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