Problem with 'tr' command

I am having a problem running the 'tr' command:

This is what I expected (tested in development environment)
Version: HP-UX sdmw728a B.11.00 U 9000/800

sdmw728a:clmdev: /apdev/clmdev/cl_be/4300/bin> x=PMRR
sdmw728a:clmdev: /apdev/clmdev/cl_be/4300/bin> echo $x | tr [A-Z] [a-z]
pmrr
sdmw728a:clmdev: /apdev/clmdev/cl_be/4300/bin> y=BACARDI
sdmw728a:clmdev: /apdev/clmdev/cl_be/4300/bin> echo $y | tr [A-Z] [a-z]
bacardi


And this is what I am getting in production environment
Version: HP-UX spfe631a B.11.11 U 9000/800

[spfe631a]/home1/d/dev_tech $ x=PMRR
[spfe631a]/home1/d/dev_tech $ echo $x | tr [A-Z] [a-z]
PMRR
[spfe631a]/home1/d/dev_tech $ y=BACARDI
[spfe631a]/home1/d/dev_tech $ echo $y | tr [A-Z] [a-z]
BxCxRDI

Why the same command behave differently on the same version of HP-UX.


Sush
Distributed Systems - CLMS Development
Phone: 302-457-5082