4GB of 'App' Space Consumed by Nothing?

[ideal.dreams]

I have an iPhone 4, running 4.0.1. When I went to sync it a few days ago, there was roughly 3GB of apps. This is including a mobile navigation app, which is about 1GB. Anyways, when I plug it in to sync and add new apps to it TODAY, it's saying I have 7GB total in apps. I did NOT download 4GB worth of apps in 2 days, I barely get that in 2 months.

My question is: What is eating up 4GB of space, and why is it being classified under the 'apps' category?

For those who are wondering, my iPhone 4 is jailbroken.

 

[ideal.dreams]

Does anyone know what the problem is?

 

[vladzaharia]

Most of it is probably the GPS App. All the apps that you download are compressed, so the GPS App is 1GB Compressed. Uncompressed, it's more.

 

[ideal.dreams]

I never knew that, thanks for the help.