Testing 2.4.1 beta 11 under Wine I can't reproduce the slow-down issue, so it looks like you fixed it.
Edit: I created logs under Wine for 2.4.1 b10 and b11 and doing this: Boot SysInfo example disk, drag screen down then up. Enable l-l vsync then drag screen down then up.
The relevant parts seem to be, for 2.4.1 b10:
Code:
23-432 [680 000x000]: Unstable vsync! 49.953194 vs 50.057980
23-572 [680 000x000]: Very unstable vsync! 50.109485 vs 33.309567, retrying..
23-712 [680 000x000]: Very unstable vsync! 50.069533 vs 33.337021, retrying..
[... similar lines omitted ...]
24-552 [680 000x000]: Very unstable vsync! 49.886362 vs 33.314217, retrying..
24-692 [680 000x000]: Very unstable vsync! 49.954240 vs 33.349600, retrying..
24-697 [680 000x000]: Unstable vsync reporting, using average value
24-697 [680 000x000]: VSync calibrated: 37.498029Hz/1.0=37.498029Hz. MinV=1 MaxV=1046i Units=31819 91.5%
24-728 [680 000x000]: VSync remembered: 37.498029Hz/1.0=37.498029Hz. MinV=1 MaxV=1046i Units=31819 91.5%
24-741 [680 000x000]: PAL mode V=37.4980Hz H=11699.3852Hz (227x312+1) IDX=10 (PAL)
24-741 [680 000x000]: P96FREQ: 312*37.4980 = 11699.3852 / 37.5 = 312
33-819 [1108 000x000]: VSync remembered: 37.498029Hz/1.0=37.498029Hz. MinV=1 MaxV=1046i Units=31819 91.5%
33-831 [1108 000x000]: PAL mode laced V=37.4980Hz H=11699.3852Hz (227x312+0) IDX=10 (PAL)
33-840 [1109 000x000]: Interlaced frame type mismatch 1<>0
33-842 [1109 223x033]: Interlaced frame type mismatch 0<>1
[... repeated many times while display interlaced and l-l vsync ...]
35-222 [1188 000x023]: Interlaced frame type mismatch 1<>0
35-253 [1190 000x000]: Interlaced frame type mismatch 0<>1
35-255 [1190 000x000]: VSync remembered: 37.498029Hz/1.0=37.498029Hz. MinV=1 MaxV=1046i Units=31819 91.5%
35-272 [1190 000x000]: PAL mode V=37.4980Hz H=11699.3852Hz (227x312+1) IDX=10 (PAL)
And for 2.4.1 b11:
Code:
58-551 [757 000x000]: VSync calibrated: 49.986279Hz/1.0=49.986279Hz. MinV=1 MaxV=1048 Units=23870 89.0%
58-579 [757 000x000]: VSync remembered: 49.986279Hz/1.0=49.986279Hz. MinV=1 MaxV=1048 Units=23870 89.0%
58-595 [757 000x000]: PAL mode V=49.9863Hz H=15595.7189Hz (227x312+1) IDX=10 (PAL)
58-596 [757 000x000]: P96FREQ: 312*49.9863 = 15595.7189 / 50.0 = 312
08-499 [1229 000x000]: VSync remembered: 49.986279Hz/1.0=49.986279Hz. MinV=1 MaxV=1048 Units=23870 89.0%
08-511 [1229 000x000]: PAL mode laced V=49.9863Hz H=15595.7189Hz (227x312+0) IDX=10 (PAL)
10-936 [1349 000x000]: VSync remembered: 49.986279Hz/1.0=49.986279Hz. MinV=1 MaxV=1048 Units=23870 89.0%
10-949 [1349 000x000]: PAL mode V=49.9863Hz H=15595.7189Hz (227x312+1) IDX=10 (PAL)
12-456 [1423 000x000]: VSync remembered: 49.986279Hz/1.0=49.986279Hz. MinV=1 MaxV=1048 Units=23870 89.0%
12-469 [1423 000x000]: PAL mode laced V=49.9863Hz H=15595.7189Hz (227x312+0) IDX=10 (PAL)
14-056 [1501 000x000]: VSync remembered: 49.986279Hz/1.0=49.986279Hz. MinV=1 MaxV=1048 Units=23870 89.0%
14-068 [1501 000x000]: PAL mode V=49.9863Hz H=15595.7189Hz (227x312+1) IDX=10 (PAL)