Thanks for your reply
I've to add, this bug was found using a PC machine with the following additions:
1. A just formatted Windows XP SP3 (Spanish)
2. No MS Office installed (yet).
3. Intel Pentium 4 (2.8GHz)
4. DirectX 9 (february /2010)
5. .NET Framework (versions from 2.0 SP1 to 3.5 SP1)
Thanks!