We have discovered that users using IE 6.0.2800 SP1 may experience some difficulties doing their login on the site. We believe this could have been triggered by a recent Windows automatic upgrade. The only solution we have found so far is to have them upgraded to 7.0. Basically, once applied, the level of security is way too high and this cannot even be adjusted from the tools option. If anyone would know how to resolve that issue, that would be greatly appreciated.