Yamaha f1 overburn problem with Datatrack CDRs

Based on the cdfreaks - review I decided to buy the yamaha f1. But trying to create an overburned cd with the same settings as used in the overburn-test (DataTrack 99min/900MB Media, Nero CD Speed) I got a real serious problem: the f1 did not recognize the Data Track Media (TOC Error Code 035700) and I didn´t even got a chance to burn (bought 5 DataTrack disks of the same type, each of them were not working). Also the drive indicates trying to read the media information (noise of re-read-action) and then quits with the indicator always on coloured as error status (not the regular blue). The only difference to the test in the setting ist my firmware 1.0d (used in the test 1.0b). All other media types up to now worked fine so far.

And there is a second issue: using Nero CD Speed’s media check test the test returns a read error rate of 33-34% (!) on the f1 with burned and also original (bought) discs. Doing the same test with the LiteOn 52x (installed in the same machine) returns a normal error rate of 0,001% (even on disks burned with the f1).

Has somebody experienced any similar problems
or hopefully has a solution (for both issues) or even an idea??? :confused: