The first downgrader was only working on most PSPs (not on E1000) and did not support a direct downgrade to firmware 6.60.
This new version of the downgrader now supports all PSPs (including the E1000) and also supports a direct downgrade from firmware 6.61 to 6.60.
Qwikrazor has pushed a proper update of Davee’s Chronoswitch downgrader, which is now capable of doing the very same as the previous version, but with added firmware 6.61. support.
The new Chronoswitch downgrader v6 supports firmwares 6.3x up to firmware 6.61, and can downgrade your PSP from up to firmware 6.61 down to firmware 5.00 (lower firmwares are currently untested), as long as your PSP supports said firmware in the first place.
Once again great work by qwikrazor! Next stops: The updated ME & LME CFWs for 6.61 and the permanent patch for firmwares 6.30+.
Source via our forums.