Using CRC32 for hashing passwords is a very bad idea. The reason is that, although CRC32 is numerically unstable, it is possible to recover information about the input. A better choice would be to use MD5 or SHA-1, but you should probably also use a salt to make it more secure against dictionary attacks.

For a good example, and more information, read section 5 in the document "The Breaking of Cyber Patrol 4", easily found on the WWW.