Slow Leopard animations

I am running 10.5.2, 1GB of RAM and a 2GHz Intel Dual Core processor. I have two accounts setup, one for general use and one set to a foreign language. On my main account I have noticed that dialog boxes (such as Save dialogs and Pages template selections) have virtually non-existent animation. Things such as minimizing to the dock work perfectly, as do other system animations, but things such as Add Bookmark in Safari have no animation associated with them.

However, on my other account (on the same laptop) the dialog boxes slide down smoothly - just like they are supposed to.

I have nearly all of my files on my main account, with virtually none on the other one. I have approximately 1GB of storage left (I know, I'm upgrading the HDD soon), but it doesn't seem to affect the other user.

How do I fix this?

The symptoms you describe lead to me ask what software (particularly startup items) you have loaded on your main account that are not present on the secondary one. What you are describing would be consistent, at least at first reading, with something hogging CPU from your first account.

Check this by loading Activity Monitor and see what your "resting" CPU occupancy is. It should be less than 3% or so. If it is higher than that, check the Processes display, sorted by % CPU, to see who is hogging the machine.

Good Luck!

User CPU is below 5%, system is below 7% at rest. On start-up, I run:

Mozilla Thunderbird
iTunes (iTunes + iTunes Helper)
Growl
iStat Menus

Once these programs have started up, I will usually open Safari, Skype and possibly Pages.