When the CRM system tries to update the recent list on an Oracle install, an error may appear in the SQL logs saying that the statement is too long:
ORA- 01704 : string is too long (character string too long )
There is a custom_sysparam called RecentListSize:
select * from Custom_SysParams where Parm_Name = 'RecentListSize'
By updating this value to a smaller value you can reduce the size of the recent list to prevent this error from happening.