The reinstall of AC on the WinXp machine did not make any difference.
Also, it seems that given enough time (15-30 minutes) with only one chart open, the next chart opened still takes about 30 seconds to open again. After that first one opens, subsequent charts open immediately still... but for a provider seeing patients it still appears to be going slow "all the time."
Next up, I will try disabling password protected sharing completely tonight or tomorrow early morning and see if that helps.
