When I look in the alert log I see this:
Current log# 1 seq# 7802300 mem# 0: /u02/oradata/O8I5A/redo01.log
Current log# 1 seq# 7802300 mem# 1: /usr/oracle/redo01.log
Thread 1 advanced to log sequence 7802301
Current log# 4 seq# 7802301 mem# 0: /u02/oradata/O8I5A/redo04.ora
Current log# 4 seq# 7802301 mem# 1: /usr/oracle/redo04.ora
Thread 1 cannot allocate new log, sequence 7802302
Checkpoint not complete
Current log# 4 seq# 7802301 mem# 0: /u02/oradata/O8I5A/redo04.ora
Current log# 4 seq# 7802301 mem# 1: /usr/oracle/redo04.ora
Thread 1 advanced to log sequence 7802302
Current log# 3 seq# 7802302 mem# 0: /u02/oradata/O8I5A/redo03.ora
Current log# 3 seq# 7802302 mem# 1: /usr/oracle/redo03.ora
Thread 1 advanced to log sequence 7802303
Current log# 2 seq# 7802303 mem# 0: /u02/oradata/O8I5A/redo02.log
Current log# 2 seq# 7802303 mem# 1: /usr/oracle/redo02.log
Thread 1 advanced to log sequence 7802304
Current log# 1 seq# 7802304 mem# 0: /u02/oradata/O8I5A/redo01.log
Current log# 1 seq# 7802304 mem# 1: /usr/oracle/redo01.log
Thread 1 advanced to log sequence 7802305
Current log# 4 seq# 7802305 mem# 0: /u02/oradata/O8I5A/redo04.ora
Current log# 4 seq# 7802305 mem# 1: /usr/oracle/redo04.ora
Thread 1 cannot allocate new log, sequence 7802306
Checkpoint not complete
Current log# 4 seq# 7802305 mem# 0: /u02/oradata/O8I5A/redo04.ora
Current log# 4 seq# 7802305 mem# 1: /usr/oracle/redo04.ora
Thread 1 advanced to log sequence 7802306
Current log# 3 seq# 7802306 mem# 0: /u02/oradata/O8I5A/redo03.ora
Current log# 3 seq# 7802306 mem# 1: /usr/oracle/redo03.ora
Thread 1 advanced to log sequence 7802307
Current log# 2 seq# 7802307 mem# 0: /u02/oradata/O8I5A/redo02.log
Current log# 2 seq# 7802307 mem# 1: /usr/oracle/redo02.log
Thread 1 advanced to log sequence 7802308
Current log# 1 seq# 7802308 mem# 0: /u02/oradata/O8I5A/redo01.log
Current log# 1 seq# 7802308 mem# 1: /usr/oracle/redo01.log
Thread 1 advanced to log sequence 7802309

What can be causing this, and how I can solve it?
I have 4 groups with 2 members each on separate drives. Size of the members is 500K. Oracle 8.1.5 on AIX.