Have you updated and downloaded the most recent Tascam Driver's? Mine works fine with PT9HD. I only use the 128 sample for monitoring while recording. It's not 0 latency, but it's so close that it doesn't sound phasey while recording. I then switch to 1024 for everyday mixing/editing. 128 should not have a delay. My guess is you need to update the driver or perhaps even as lame as this next suggestion is, trying a new different USB cable and slot? Make sure you're going direct into a USB 2.0 jack on your computer with a USB 2.0 cable.
After double checking all of that, if it still sin't working correctly try it with another program and if see if it's still an issue (so you can islolate whether it's PT10 causing the issue or the Tascam). Get Audacity Free. That's what i use to to test my hardware with if I am experiencing any issues so i can isolate the problem. If it's doing the same thing in Audacity, it's the Tascam. Call up their tech support - they actually speak English and answer the phone! Oh and they usually solve your problems! What a concept in this day in age!
If it's not the Tascam, it's probably PT10. Get in touch with their community.
Audiofire12 | GAP Pre73 | Pro MPA II | Pro VLA II | dbx163X | Presonus M80 | iMac | 2xBCF2000 | PT9HD | Big Knob | M-Audio BX5a Deluxe & Minimus 7 Monitors | Pug named Ruby