It seems fine when map scale is at 1:90 000 but lagging occurs once map
scale is set to 1:500 000 or 1:1 000 000.
For "Add map layer" dialogue window to pop out, it takes 6 seconds on my
machine (CPU=2.66GHz and RAM=512MB running WIN 2003)
This is true both for Pre-compiled QGIS 0.81 and source-code compiled QGIS
When adding a shapefile of 10MB, it takes 11 seconds to start to show up
and 21 seconds to complerte the loading. It also shows an error message at
the 11th second, stating (The error message is
[Warning:QgsSpatialRefSys::getRecord failed:select * from tbl_srs where
parameters='+proj=utm +zone=51 +south +ellps=GRS80 +units=m +no+defs']
I am keen to learn whether this error has derived from my compilation or
the software itself.