Some rollback segment errors (1551,1595) urgent

Dear Fellow Dba's
I had the following errors in my alert logs.while running some transactions.
The database have 40 rollback segments with 5mb each (initial 500k,next 500k minextents 10 maxextents 250)

• SESSION ID:(6.1) 1999.11.05.08.09.03.000 SMON: following errors trapped and ignored: ORA-01595: error freeing extent (536871148) of rollback segment (158)) ORA-01551: extended rollback segment, pinned blocks released got it by 8 o clock

Thu Oct 28 09:11:36 1999
Thu Oct 28 09:11:36 1999
*** SESSION ID:(6.1) 1999.10.28.09.11.36.000
SMON: following errors trapped and ignored: ORA-01595: error freeing extent (536871148) of rollback segment (159)) ORA-01575: timeout waiting for space management resource got it by 9 o clock

Can you please tell How can i rectify the problem.

I have created a new rollback segment of size 100mb & ask the client to put SET TRANSACTION USE ROLLBACK SEGMENT RBS_40 before thier sql statement . Is it correct?.
Please give some clues & hints. Any immediate hints will be appreciated.

John D Received on Fri Nov 05 1999 - 09:57:05 CST