raid1: how to check for filesystem errors?

I have a raid1 system with 2x 400GB SATA drives. System has been frozen several times in the last 2 weeks. I have been checking memory overnight, no problems, checked harddisks with manufacturertools, no problems found. So I think, that maybe there is something wrong somewhere in the filesystem, but how do I check? Using reiserfsck from rescuedisk on the partitions does not work. Running the rescuedisk does not freeze the system btw. So I do suspect (one of) the harddrives. What can I use to check?? -- L. de Braal BraHa Systems NL - Terneuzen T +31 115 649333 F +31 115 649444