Clover issues with any build more recent than 4128

I'm starting the preliminary work to upgrade to 10.13, and I'm running into problem with clover. Any build <= r4128 works fine, but as soon as I go above that I get a simple line of '+++++++'s and then...nothing - the screen just hangs. I can reinstall the older version next boot and I'm fine again Same for safe/single user mode and with pretty much any combo of hfsplus /vbox64 and the various OsxAptio* drivers but with an identical result. Any help or insight is much appreciated