As I checked, if there are also too many kinds of cellStyles in ods, it will also take several minutes to open the ods file.

2012/8/30 bjcheny <>
Hi guys,

I am fixing bug 120619, which is about Aoo takes too long time to open xlsx file.
The root cause is that sample file has up to 28380 cellStyles/cellStyleXfs, though nearly no reference to them at all.

A question came up when I tried to figure out a solution:
Shall we set a limitation here? 
When we export xls file by Aoo, there is a limitation of 4050. It seems reasonable because MS 2003 Excel can't support too many cellStyles.
It can be proved by indication provided by MS 2007 Excel when you save sample xslx as xls, as attached pic.

Thus, I really need your opinions. Or can there be a better solution?