Data::Alias was generally broken in 5.18.x (CPAN Testers Reports confirm this).
This seemed to affect quite a few people: there've been a number of posts about this.
Version 1.17 of Data::Alias appears to have fixed the problem; again, CPAN Testers Reports seem to confirm this.
Priority 1, Priority 2, Priority 3
Priority 1, Priority 0, Priority -1
Urgent, important, favour
Data loss, bug, enhancement
Out of scope, out of budget, out of line
Family, friends, work
Impossible, inconceivable, implemented
Results (93 votes),