New iPod, Created Playlist on iPod, Now Can't Delete???

Question

When i dock my ipod in itunes and i click the triangle to reveal the sub playlists i can see one i created earlier but i want to delete it but can't.
i created a playlist called "Purchased" because i wanted an easy way of playing just the songs i purchased from itunes. However, once created i see no way of deleting it as all the songs in the playlist is grayed out. In fact all the songs in all the iPod playlists are greayed out. My "Purchased" playlist is full of songs and i don't want to lose any. I created an iTunes playlist and successfully deleted that but therefter i was unable to sync as itunes told me it could not sync because not all the playlists could be found and i also lost all my songs on ipod at the same time? So i formated my ipod and started again but the old "Purchase" playlist is still there on my ipod???
Please help
Paul.
AMD 4000+   Windows XP  

Answer 1

I thought I got this sorted but I havn't and need help.
For the second time tonight and much to my annoyance I have lost all my songs in my ipod. Let me tell you how this is happening.
From iTunes I selected the option to "Manually Manage Music and Videos" in order to delete a playlist i no longer want. I then deleted the playlist "Purchased" from the left hand side under DEVICES. All is fine until I uncheck "Manualy Manage Music & Videos" again in order to re-sync automatically. It's at this point the "Purchased" reappears it's ugly head and I then lose all my files from my ipod.
Under the music tab in iTunes the pre defined playlists plus the one i created "purchased" always remained their and I have no way of deleting them even if i delete them from the DEVICES column on the left hand side once i select Manually Manage Music etc.
Can anyone help please??
Paul.