Perl magic

Since i am perl-intern, perl is my second language :)
Some of it is very strange!
For example, pattern /^\w+(\d+)\w$/ match one string blabla01d and doesn't match blabla10d. I know, that \w can match digits also, so I made /^\w+?(\d+)\w$/, so it worked on MY machine. But on other computers first pattern aslo works fine.
So I DON'T KNOW WHAT IS HAPPANING!

Kill me by wall...(c)