If you need partitions larger than 2 TB you need to change the disk from MBR to GPT. This can only be done on an un-partitioned HD, so I would remove all partitions from it and start the 2008 installation again. You should get the options to change the disk to GPT where you select the disk and partition during installation.
http://technet.microsoft.com/en-us/library/cc738416%28WS.10%29.aspxAlso, I wouldn't use Dynamic disks unless you have a good reason for that.
