On the other hand, the LCD problem now appears even on 416 MHz which makes me think the PCMCIA timing recomputation has some other bug. Maybe, the timing is now too tight so the PCMCIA device takes too much bus bandwidth, triggering the LCDs FIFOs underruns.
There is one more thing that brings me to that conclusion, that is, when I ran a hdpart -T /dev/sda on the harddrive attached to PCMCIA, I got the following results:
|Frequency||Read speed without fix||Read speed with fix|
|416 MHz||8 MB/s||12 MB/s|
|208 MHz||2 MB/s||4 MB/s|