Booster has updated his awesome loader - Devhook to version 0.41a. Here's whats new:

Fixes game selection from XMB with Home + L/R Triggers
Bug corrected where wallpaper isn't restored after PSP is put in sleep mode.
Fixed a bug where the ISO isn't changed properly.
WiFi doesn't work when the PSP is overclocked (yet).

You will need the original Devhook 0.41. Download it from here:
http://pspupdates.qj.net/Newer-UMD-Games-and-Browser-come-to-1-50-PSP-s-/pg/49/aid/51671