I recently downloaded and installed QGIS 2.4 Chugiak on a Windows 7 64-bit machine with a quad core processor and 8GB RAM.
I'm having a few problems using datasets of all sizes from a network drive - the data is slow to render and there is an annoying low-pitched "beep" each time I zoom in/out. In the previous release (2.2), this network data would render almost instantly for small datasets with no sounds.
I've also noticed that opening the attribute tables for this network data is very slow. E.g. a dataset with just 91 records takes almost 30 seconds - something that was almost instant in QGIS 2.2 Valmiera.
Using the dataset on a local drive removes the problems, though this is not an option as we have several members of staff working on the same datasets and want to avoid having multiple file versions all over the place!
Have any network settings been changed from 2.2 to 2.4?