I think its the old story of how much data you have - I have hundreds of ads and it takes an age to login - always.
Bingo, benflux!
Here are some tips for faster loading. Before logging out of your account, at least consider doing some of these things to minimize load time at your next login:
* Set your date range to 'today'. This is a whole lot less info than 'all time' in a large account.
* When you have the option as to how many of something to show, set it for the lowest number. (i.e. minimum number of keywords instead of all of them.)
* Select 'Show only active campaigns' rather than 'Show all campaigns'.
* Select 'Show only active Ad Groups' rather than 'Show all Ad Groups'.
* Uncheck the 'include deleted items that were active in this date range' box at the Ad Group level.
Doing these things will minimize the amount of data that must be pulled from the database during login - and will speed things up in large accounts.
Important note: exceeding the suggested maximums for number of Ad Groups and keywords can also really slow things down. These suggested maximums have been posted in this forum quite a few times.
Hope that helps!
AWA