Ardour "not fast enough"

I installed 64 Studio 2.0 which includes Jack and Ardour 2. When trying to select latency, the 256 setting (5 ms) setting is not available. Also, tons of errors on very simple projects stating Ardour was not fast enough.

What’s going on? Is it a 64 Studio glitch. I used Ardour .99 with 64 Studio 1.0 which worked perfectly.

The load on the DSP is less than 2 percent during playback.

what audio hardware?

Delta 1010LT – The same as was used with .99

Well, maybe you should try 0.99 on the same system (64 Studio 2.0). you can install them side-by-side without any issues.
Or at least, you’re supposed to be able to - it depends on what the distribution has done.

I suspect you have system configuration issues, but there isn’t enough information or time in the day to speculate on precisely what they might be.