iPod Mini 2G with CF card mod - big lag when choosing song

[cybtrash]

Hello,

I bought a used iPod Mini 2G and a CF card (Komputerbay J8 128GB COMPACT FLASH CARD CF 1050x WRITE 100MB/s READ 160MB/s Extreme Speed UDMA 7) (no SD card / no adapter).
I installed Rockbox DEV.
I transfered lots of songs, mostly MP3 and FLAC, around 3500 songs.

Now I am facing those problems:
- Choosing a song / skipping to next song takes some time, around 2-7 seconds

With the original firmware there is no delay, everything is very smooth.

Did I do something wrong? Did I miss special settings for CF card?

With those big delays Rockbox can't be used properly. But I would like to keep it because of better EQ, crossfade and so on.