Well its not BS, Imagine trying to configure and support 10s, maybe 100s of users HOME hodge podge configurations with out even seeing them and knowing that most are not set up right, the man hours would be INSANE.
Anyway, we need some more info
What operating system are you using?
Like was said, your company is probably using a workgroup if not a domain and the settings are completley different from your home network. As was said by anoter poster, your router is probably set to assigne address by DHCP and serve DNS. Win XP Pro has a setting I saw that allows you to configure for multiple networks using profiles but I have not played with it yet. If you read your documentation for your router it should tell you how to set your IP settings to work with your network but youll need to remember your current settings for your work network. If your running an older OS there are 3rd party softwere that allow you to set and then choose network settings profiles at boot time (wich is when they must be applied to work in most cases) . I use GLOBESOFT MULTINETWORK MANAGER on my laptop to manage like 14 different network config profiles for all of our different sites and it works very well.
http://www.globesoft.com/software_products.html
Your other opting is to use a second netowrk adaptor to connect at home wich may sound nuts but if you use a wireless network at home, youll need a wireless network card or USB device anyway and the two adaptors will have separate TCP/IP settings. There may be a problme if your company uses a Domaine though.