Partitioner Should Resize Partitions

I have a 500 GB hard drive with WindowsXP already installed. With the Released Ubuntu 7.04 CD inserted and the computer restarted the Ubuntu installer is started. I answer the simple questions and wait for the partitioner to offer to split the 500 GB drive and resize the partitions. The partitioner only offers Guided using the entire 500 GB hard drive for Ubuntu or manually partitioning the hard drive. The partitioner only offers the solution of devoting my entire 500 GB drive to Ubuntu. Previously the Beta version offered to split the 500 GB by resizeing it into two partitions, one windows and one Ubuntu, and I could select the size of each partition. I'm trying to get that splitting of the hard drive to start with the released version. My attempt to manually partition the drive into two partitions fails.

My Computer:

Velocity Micro Vision 64™ High Performance Home & Office PC
AMD® Athlon™ 64 X2 5000+ 2.6GHz Processor with Dual Core Technology, AM2
Creative Labs SoundBlaster® X-Fi™ XtremeAudio
Asus® M2N SLI Deluxe - NVIDIA® nForce™ 570 SLI MCP, PCI Express Motherboard with DDR2, socket AM2
512MB eVGA™ NVIDIA® GeForce™ 7600 GS, Dual Heads
500GB Hitachi 7200RPM SATA/150, 16MB Cache
16x Lite On® DVD+/-RW/CD-RW Dual Layer, Black Bezel
Genuine Microsoft® Windows® XP Home SP2