Emacs perl-mode bug?

[Brian M Tyrrell]

When using perl-mode in emacs 21.3.1, I was trying to use the ${varname} 
syntax within a pattern replace to avoid butting $varname against the 
subsequent text.  This seemed to confuse the delimiter matching, which 
matched the closing "}" to the first "{" that it found before 
"${varname}" instead of the "{" after the "$".

Is this a bug in the perl-mode, or am I just confused about my syntax?

Thanks.