What's mean this error in percona logs

Hi,

I don’t know what’s mean this logs errors :
120614 15:25:55 [ERROR] Slave SQL: Could not execute Delete_rows event on table pa.AreaType; Cannot delete or update a parent row: a foreign key constraint fails (pa.Area, CONSTRAINT fk_Area_AreaType FOREIGN KEY (areaTypeId) REFERENCES AreaType (id) ON UPDATE CASCADE), Error_code: 1451; handler error HA_ERR_ROW_IS_REFERENCED; the event’s master log FIRST, end_log_pos 129, Error_code: 1451
120614 15:25:55 [Warning] WSREP: RBR event 2 Delete_rows apply warning: 152, 1925
120614 15:25:55 [ERROR] WSREP: Failed to apply trx: source: 938778e1-b61c-11e1-0800-00d9733f9bb3 version: 2 local: 0 state: CERTIFYING flags: 1 conn_id: 1673 trx_id: 17946 seqnos (l: 364, g: 1925, s: 1924, d: 1906, ts: 1339680355633397546)
120614 15:25:55 [ERROR] WSREP: Failed to apply app buffer: cæÙO, seqno: 1925, status: WSREP_FATAL

120614 15:28:23 [Warning] WSREP: Certification failed for TO isolated action: source: 938778e1-b61c-11e1-0800-00d9733f9bb3 version: 2 local: 0 state: MUST_ABORT flags: 65 conn_id: 1673 trx_id: -1 seqnos (l: 4, g: 1930, s: 1929, d: 1929, ts: 1339680357271361415)
120614 15:28:23 [Warning] WSREP: Certification failed for TO isolated action: source: 938778e1-b61c-11e1-0800-00d9733f9bb3 version: 2 local: 0 state: MUST_ABORT flags: 65 conn_id: 1673 trx_id: -1 seqnos (l: 6, g: 1932, s: 1931, d: 1931, ts: 1339680357309181941)
120614 15:28:23 [Warning] WSREP: Certification failed for TO isolated action: source: 938778e1-b61c-11e1-0800-00d9733f9bb3 version: 2 local: 0 state: MUST_ABORT flags: 65 conn_id: 1673 trx_id: -1 seqnos (l: 8, g: 1934, s: 1933, d: 1933, ts: 1339680357347609350)

Thx for ur help

What version of XtraDB cluster are you running?

hi,

This is Percona 5.5.24, the last version

Thx