As I've posted to several PPC boards, I've found a nasty bug in NetFront 3.1 (from now on: NF) with flaky caching/reloading, which makes using NF 3.1 far more bandwith-consuming than an in this respect bugless PPC browser (for example, Pocket Internet Explorer (PIE) or NetFront 3.2).
If you navigate to a previously visited page which still exists in NF's cache, the changes to the page will NOT be visible at all - the server always answers with a 304 Not Modified message. I've tested this several times with modified HTML pages. The changes have never been displayed without explicit reloading. If you force a reload of the page (click the Reload icon), on the other hand, all files will be downloaded again, regardless of their being modified or original, resulting in excess (and, again, unnecessary) bandwidth hit. In this respect, both PIE and NF 3.2 is much better.
Fortunately, in the latest (still Japanese only) version of NF, 3.2, this bug has been corrected.