Measurement & Automation Explorer does not change the VISA Configuration from itself. It is meant that those settings are only changed when M&A is open and the user requires a rescan or removes or disables devices explicitedly. It is always tricky to do full autodetection and automatic configuration adaption without sometimes loosing carefully edited configuration items.
As to the delay I have seen that too, but assumed that it was a standard VISA 3.0/LabVIEW 7.0 problem. It's interesting information that this may have to do with (default or stale) information in the visaconf.ini file to non existing resources. Rolf Kalbermatter
