Perl script freezes when accessing a USB serial port

Binary package hint: perl

I have the MyBlaster.pl that controls IR blaster. it was working fine on Ubuntu 10.04. now it freezes
The following subroutine is called and freeze:

my $serial=init_serial("/dev/ttyUSB0","19200");

The first few line of this subroutine are:

sub init_serial {
        my($port,$baud)=@_;
        my($termios,$cflag,$lflag,$iflag,$oflag);
        my($voice);

        my $serial=new FileHandle("+>$port") || die "Could not open $port: $!\n";

The call to New FileHandler fails, which is in

IO::File::new(/usr/lib/perl/5.10/IO/File.pm:35):

In the subroutime new, when performing open()

It freezes in that routine.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: perl 5.10.1-12ubuntu2
ProcVersionSignature: Ubuntu 2.6.35-22.32-generic 2.6.35.4
Uname: Linux 2.6.35-22-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Mon Sep 20 22:41:24 2010
InstallationMedia: Mythbuntu 10.04 "Lucid Lynx" - Beta amd64 (20100318)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: perl