Last Update: BrowserUK: this reproduces the errors, err, warnings I've received

perl  -e 'use warnings; $teste=q(\Qfoo\E);print 42 if "(foo" =~ m/\b$t
+este\b/'
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1. The "\b" is not the problem... It used to work before my "\Q...\E" problem.
update: At least I thought I worked. All my regexes should have \b...\b as boundaries... I think if they were interpreted as backspaces, the entire regex would never match (text don't have backspaces), and we would've noticed the absence of filtering. (the program is a kind of filter)

2. The code is a real copy-paste from my program. What i've ommited was unimportant (for example, DB queries, what i do with the return value, etc...).

3. I don't know why you say the content of $regex has to have "double slashes"... below is an example where the content of $x has only 1 slash and the printed version has 1 slash too

perl -e '$x =  q(\b); $y = "$x"; print $y'
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Update:Ok, I know the two, '\b' and "\\b" are equivalent. The point is, there is no "..." involved. I think when i get a string from a DB it comes as a '...', and putting it inside a "..." doesn't interpolate it's own content