Need a new video card

[jarvis24]

Sagelab--just out of curiosity--have you tried running a test session with a smaller resolution (e.g., 1024 x 768) to see if that eliminates the occasional 28ms stimulus? Also, did you ever find it made a difference as to whether you specified it in the input file as 1ms or 15ms?

[liminal-user]

Just double checking:

You are using a CRT, correct?

If you are an LCD you may be getting sporadic input lag. Stimulus presentation times are only ever approximate on an LCD.