Worksheets not being added

I have a macro that adds new worksheets during its execution, but it stops adding sheets at 189. With 1GB of RAM and empty sheets being added, I should be able to get much higher than 189. What's more frustrating is that after the limit has been reached and the macro is done, I can manually add many more sheets to the workbook without any problems. So why can't the macro do it?

Please post your macro.