the HDSPM driver seems to be broken in the current ALSA release. We're using CentOS 5 with 2.6.33.9-rt31.64.el5rt and ALSA 1.0.24 compiled from source, the card is a PCIe Hammerfall DSP MADI (rev d2). As already mentioned in [1], the card operates in master mode, but the system clock mode can't be set to anything higher than 48kHz.
i can switch to 192k no problem, but if i start jack while at 48k, i can only go down, not up. my guess is that i had a half-dead jack around when i tried to reproduce your issue. andre, can you confirm you do not have any processes running on the card when the problem occurs? i guess lsof /dev/snd/* might be useful...
There's an easier way to acquire this information:
$ cat /proc/asound/default/pcm0*/sub0/status
If it reads "closed", then nobody is using the card, otherwise, there would be an entry for owner_pid, thus preventing the card to change clock modes outside the multiples of 32/44.1/48 (*1, *2 or *4 depending on SS/DS/QS).
Ciao