Okay, here's the conclusion of my tests ("dead" Nova-CI budget cards):
Gentoo-Kernel 2.6.13-r2, current CVS driver -> Video Data Stream Broken Gentoo-Kernel 2.6.12-r9, current CVS driver -> works a charm Vanilla Kernel 2.6.14-rc1, built-in driver -> Video Data Stream Broken Vanilla Kernel 2.6.12.6, current CVS backpatched -> works a charm
Same goes for older CVS drivers. All Kernels were configured using basically the same 2.6.12 .config and defaults otherwise.
Definitely(?) a Kernel issue. Where to report such a thing? (I most probably won't want to be stuck with 2.6.12 forever...)
Good Night Stephan