Well, from your output, you appear not to get any spurious characters anyway.

When I said above that Data::Dumper was not the issue, what I meant was that I was just using it to display the output. I originally observed the problem because the characters added to my regex were **, which caused the regex to be invalid (luckily, or I might not have spotted it for a while).

However, Data::Dumper may yet be involved. When I run the following code:

use Data::Dumper;
my $re_bad  = qr'xx([A-Z$#@_!]*) (?! [A-Za-z0-9$#@_] )'x;
print $re_bad;
[download]

the output is:

(?x-ism:xx([A-Z$#@_!]*) (?! [A-Za-z0-9$#@_] )#
)
[download]

Note the spurious hash (or pound, if you prefer :-) at the end. Given the following code:

my $re_bad  = qr'xx([A-Z$#@_!]*) (?! [A-Za-z0-9$#@_] )'x;
print $re_bad;
[download]

the output is:

(?x-ism:xx([A-Z$#@_!]*) (?! [A-Za-z0-9$#@_] ) 
)
[download]

However, this does not yet prove that Data::Dumper is the culprit. Given the sporadic nature of the symptoms, it may well be that simply using any module of the right "size" will produce the error.

Kevin