Error Report : Excel module

I tried to use Excel Module, and found error, therefore I would like to report this.

I tried to display the contents of a datatable (about 50 rows and 4 columns), but the contents were not fully displayed. Sometime about 30% of the contents were displayed and remainings were blank. Sometimes 50% of the contents were displayed, and so on. Everytime the volume of shown contents were different and not stable.

I think, the speed of reading database contents is quite slow overall when using this bubble server (always takes 2-8 seconds to show data from database (ex. repeated group)) , and I guess this might be related with this problem.