Created Unassigned: System.OutOfMemoryException in v0.68.0.10, regression? [8808]

Hello,

In order to improve the speed of reading/writing of Excel files, I have recently updated ClosedXML from v0.64.0.0 to v0.68.0.10.

The kind of Excel file that I deal with is a big file, embedding a lot of VBA code ; I use it as a template, filling only 2 sheets with raw data (number or string, no formula).

The VBA developper improve this file continuously, for some files there was a huge speed difference, but we have arrived in a point where :

- With v0.64.0.0, we have the good results, but it is very slow
- With v0.68.0.10, the memory is increasing and then a "System.OutOfMemoryException" is thrown.

The exception is thrown in the code below

```
public XLWorkbook OpenExcel(MemoryStream xlsStream)
{
return new XLWorkbook(xlsStream, XLEventTracking.Disabled); //RR 13/06/2013 Turning off events
}
```

with v0.64.0.0 the memory is not increasing a lot during this operation (quite stable), but with v0.68.0.10 the memory used is increasing a lot (1 more GB) and then the exception occured.

I try to turn of the events, but it doesn't change anything.

Does anyone else had this issue before?

Thank you very much for your help.

Regards,
Renaud