[CentOS] What's going on with my Linux Swap?

I've tried to create a Linux swap file, but when I run fdisk, it looks 
like this:
   Device Boot      Start         End      Blocks   Id  System
/dev/hdb1   *           1        3644    29270398+  83  Linux
/dev/hdb2            3645        3737      747022+   f  W95 Ext'd (LBA)
/dev/hdb5            3645        3737      746991   82  Linux swap

Why is this W95 partition existing in the same place as my Linux swap? I 
would have thought they'd be incompatible.
Can my Linux OS use this Linux swap?

Does this need cleaning up, and if so how?

Dave