Description of problem:
Installer ends up doing a minimal install without yum, X etc.

Version-Release number of selected component (if applicable):
F10 Preview

How reproducible:
Requires / selected to not have enough space to install the chosen packages.

Steps to Reproduce:
1. Trying to use a customize packages later install.
2. Installer notices during preparing transaction that there is not enough disk space [120MB], choose to [go back].
3. Package selection screen is shown.
4. Because the screen takes >15 seconds until it is ready, thought I may not have clicked it properly and clicked the Next button.

Actual results:
1. The screen showed properly for a moment before moving to the next {installer} screen. 
2. Installation preparing transaction begins, completes quickly, and then install of x/300 packages begins.
3. System ends up being a basic text mode boot without yum/X etc.

Expected results:
1. Shouldn't be able to preclick a button (next) before the screen becomes visible.
2. Since installer knows that there is currently more packages selected than will fit, it should require reduction of the package selections before allowing to continue to the begin the install process.
3. Installer should not unselect packages automatically, causing the equiv of basic text mode install.

Additional info:
Occurred on a 3.6G HD on vmware guest, with default package selection.