Thanks for the response.
The only problem that [I think] I have with your suggestion is that the extended partition contains the logical drive d: (100% of the extended parition as you guessed), and I use D: for Windows data files (in case I have to reinstall WinXP - the O/S is on a separate partition). If I move the unallocated space to D:, I would still end up wiping D: altogether, correct?
Or, If I understand your suggestion, I will end up with a very large extended drive that can be split into the 3 logical drives that the install needs (/, /boot, /swap), correct? If I want to keep my data partition for windows, could I just split that very large extended drive into 4 logical partitions - 1 for Windows and 3 for Linux?
Could I also just take the unallocated space and make another extended partition, or is the catch that you can only have one extended partition per physical disk?