I'm going to assume that you have the Sigmatel 92XX intergrated card. I have a Dell E1705/9400 (mine's a 17" screen, yours is the 15" version).
I had the same error. There IS a workaround and it's not that difficult.
Download the necessary files from this link.
I used the sndkld_releng6_i386_lowlatency.tar.gz for PCBSD 1.3. You'll also need the soundcard.h file saved to your computer (so right click and and save as.. instead of just clicking it).
There are directions on the site. Disregard the first step (known as step 0) as it doesn't apply to PCBSD. I found it easiest to untar (think unzip...don't know if you're a recent Windows convert or not) the files into a folder first.
Then, click the start/BSD logo button and go to System--->More Applications---->File Manager - Super User Mode. Go to the folder you untared the files to...BUT WAIT! Assuming you untared it to somewhere in your home folder, you can't just go straight to your home folder the way you'd think. Once you're in the File Manager, you will be in the root (main file systems). You will have to choose home---->(your login name)----> to whatever the folder you extracted the file to.
Then just follow the directions as prescribed. Also, for number 3, that should be done in the Konsole terminal...it wasn't very clear, but just open up the Konsole and type that in. If it doesn't work, I'm not even sure if I did that step...so maybe you don't need to. I can't remember now.