package firmware-b43-installer 4.150.10.5-5 failed to install/upgrade: subprocess installed post-installation script returned error exit status 4

[Nisarg]

Dell and Ubuntu don't go with each other as far as wifi is considered. Worked hard to get wifi working on previous Ubuntu version10.04 and here i m working again with Ubuntu11.04.
Uninstalled 'bcmwl-kernel-source' and was trying to install 'firmware-b43-installer' to solve my wifi issues.

ProblemType: Package
DistroRelease: Ubuntu 11.04
Package: firmware-b43-installer 4.150.10.5-5
ProcVersionSignature: Ubuntu 2.6.38-11.48-generic-pae 2.6.38.8
Uname: Linux 2.6.38-11-generic-pae i686
NonfreeKernelModules: wl fglrx
AptOrdering:
 b43-fwcutter: Install
 firmware-b43-installer: Install
 b43-fwcutter: Configure
 firmware-b43-installer: Configure
Architecture: i386
Date: Sun Sep 18 13:32:53 2011
ErrorMessage: subprocess installed post-installation script returned error exit status 4
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
PackageArchitecture: all
SourcePackage: b43-fwcutter
Title: package firmware-b43-installer 4.150.10.5-5 failed to install/upgrade: subprocess installed post-installation script returned error exit status 4
UpgradeStatus: Upgraded to natty on 2011-08-14 (34 days ago)