I've read the thread and didn't see an issue similar to mine...
Since LT+ got out I've reflashed quite number of 360s, but the very first two weren't perfect.
I used JF 1.76 and the first one couldn't run AP2.5 games. I haven't had an AP2.5 (it was burning at that time) game and tried with the customer's one, so I decided that he might not patched it well. The second 360 gave E64 once, and after reflash worked fine, but I still didn't have a copy to test (he later had no problem with ap2.5 games). All other 360s were flashed flawlessly with 1.76. No errors, no nothing.
But the first one couldn't run any ap2.5 game. I've tested it with a game I ran on all other 360s, and several other working ap2.5 games. No luck. It runs old games perfectly but no ap2.5 as if it was with LT, not LT+.
I've flashed the drive several times with 1.76, 1.74, dosflash. I've used a test drive and the original drive (both lite on) with no luck. Sometimes the damn thing gets into E64 when powering on and I even changed the sata cable to be sure, but no luck.
The drive is 83850c liteon version 1.
Tomorrow I'll test it in a colleague's shop to see if he can flash it, but I'll appreciate any ideas

Thank you in advance, and of course one big thanks to c4eva for the release.