Automated graph distortion
 

I posted this under misc and got no response so thought I would try here.

I am creating automated graphs by updating ranges and moving objects in a VBA
loop with a time delay loop to slow it down (just doing a few thousand trig
functions). After I make the changes, I refresh the chart. It normally works
fairly well, but there are two problems:
1. The refresh periodically hangs up. The macro is still running but the
graph does not refresh. (Stops different places different times)
2. Some of the object's sizes get distorted.

I added an export to the loop to write each frame to a .jpg and the
distortion really went crazy (on the display and in the jpg). If I take out
the refresh and the timer loop the jpg files come out fine.

I have tried it on several different computers with similar results.
Using Excel 2003 in XP Pro

Has anyone else experienced this kind of problem? Any suggestions?