v2 — community-validated, now Classic-safe.
Since v1, the fix has been confirmed rock-solid on multiple G4 minis — one tester ran 30+ restart cycles with zero freezes, and toggling it off brought the freezing right back (thanks to the testers on the MacOS9Lives thread).
New in v2: a guard so the fix cleanly no-ops under the Classic environment (Mac OS X). It fixes a hang reported when booting an OS 9 partition via Classic on Tiger — under Classic the display is virtualized and the enable call has no real hardware to drive. On native OS 9 nothing changes: the guard can only skip the fix under Classic, never suppress it on real hardware, so v2 is a safe drop-in over v1 for everyone.
Which file:
VBLFix_v2.img— the fix (silent everyday version). Drop VBLFix_v2 into System Folder → Startup Items.VBLAutofix_v2.img— tester build (beep + log).
.img disk images preserve the Mac resource forks (recommended); .bin are MacBinary equivalents. Native behavior is unchanged from the validated v1 — the v1.0 release is still there if you want the previous build.