output to digibeta framerate problem

I'm having the hardest time doing insert edits to an A500 without there being a framerate problem. My sequence is 720x486, the fields of all the footage is set to lower and all resolutions match. If the show is output from top to bottom, it's fine, but if an insert has to be done to fix something, the framerate on the edit looks like 24p. This can only be seen on a CRT, also. The progressive LCDs don't show it. The issue only seems to be fixed by logging out and logging back into the computer. Anyone else experienced this problem and find a solution? It's making everything take longer than it should and it's not consistant. I could at one point see the sequence played out before it went into tape and it looked problematic on the deck monitor, but not on the canvas in FCP.