miro/Pinnacle capture driver issues

You may experience abnormally slow UI response with this driver when using overlay display mode and dialogs or menus overlap the display window. Switching to Preview mode will avoid this. Also, under Preferences, the Disable preview/overlay for menus and dialogs option may be helpful, as it attempts to automatically disable video as appropriate.

Zoran capture driver issues

Some versions of this driver round off frame rates to the nearest millisecond period. For instance, specifying 15 fps as the desired frame rate may result in an actual capture rate of 14.925 fps (67 ms/frame) or 15.152 fps (66 ms/frame). The capture settings dialog has a "round" button to help you specify an attainable frame rate, avoiding frame drops that would otherwise occur due to the discrepancy. The Quick FPS menu at the bottom right of the window also has frame rates pre-rounded to milliseconds for convenience.

Brooktree/Conexant BT8x8 driver issues

The BT8x8 series of video capture chips can't capture the same video data to both memory and the display at the same time. As a result, attempting to capture both fields (height >240 NTSC or >288 PAL) while Overlay display is enabled may result in the overlay stopping or strange errors appearing. Use Preview mode or disable display in order to capture both fields.

Note that this may not apply to you if the chip is integrated into your video card.