did you activate cperl-hairy?

try C-h v cperl-hairy to check the variable, for me it's nil (deactivated)

cperl-hairy is a variable defined in `cperl-mode.el'.
Its value is nil
 
Documentation:
*Not-nil means most of the bells and whistles are enabled in CPerl.
Affects: ...  `cperl-electric-keywords' ...
[download]

alternatively you could switch off "abbrev-mode"!

Uses `abbrev-mode' to do the expansion.

UPDATE:

Interactively M-x cperl-toggle-abbrev should always do and is also accessible via clicking the menu Perl / Toggle / Electric Keywords or by shortcut C-c C-k!