Update Apps on iPhone4 Using iTunes

Having trouble updating apps on iPhone4 when connected via USB cable and using iTunes.

These steps work:

1) Launch iTunes.
2) Click on Apps under Library in iTunes.
3) Click on Download All Free Updates at lower right of iTunes window (I think that was the caption; it's changed now since I completed this step of the process).
4) Login to iTunes store so that all App updates can download properly. They do.
5) Connect iPhone4 to Mac using USB cable.
6) Click on iPhone4 under Devices, and select Apps button at top center of iTunes window.

Here's where things don't work:
7) Sync Apps.

Rather than updating my iPhone4 with all the App updates that I've just downloaded from the iTunes store, the Apps on the iPhone4 remain at their old version, and the App Store App on the iPhone4 remains tagged with a red number indicating the number of Apps that have updates available.

The iPhone4 apparently wants me to do the updates via WiFi or 3G. I don't have a WiFi network readily available, and doing the update via 3G is painfully slow. Obviously, I should be able to update the Apps on the iPhone4 via iTunes and a USB cable, but (as described above) it doesn't work.

My workaround:

8) In iTunes, delete one App from the iTunes window depicting the iPhone4 screens.
9) Sync Apps.
10) Add the deleted App back in the iTunes window depicting the iPhone4 screens.
11) Sync Apps.

Any ideas why the updated Apps in iTunes don't replace the outdated ones on the iPhone4 when doing a ordinary (vs. workaround) sync? Either iTunes or the iPhone4 seem to think that nothing has changed with my Apps (and so skip syncing them), until I force a change (i.e., get a "new" App).