Using PS 7.1.0 on craftbukkit 1.0.1 and tekkit I can no longer place "stones". All other functionality however seems unaltered. I can re size existing fields as well as edit flags of stones. I can even break placed stones. Only the placement of new ones is not working. "/ps on" is set Using default settings. No errors in console or in game.

Check again with R3, don't think this was an issue with tekkit so much as an issue with the bugged cb1.1 R1-R2. Let me know if it keep shappening with CB1.1-R3

Well once Tekkit updates to 1.1.0 allowing me to use cb 1.1 I shall do so. Thank you.