Update Failed error Message (UpdateSQL)

Hi Everybody,

Im using a dataset (TQuery) linked with an UpdateSQL. The query have a
join clause and CachedUpdates property setted to TRUE. When I use
ApplyUpdates and CommitUpdates methods in a record changes succeed. However
if I try to change the same record again and call ApplyUpdates, Delphi
raises the message below:

"Update Failed".

PS: Im using Sybase System XI and Delphi 2.0 Client/Server.

I thought this message very subjective. Please, can anyone (TeamB) tell me
when or why it happens ?

Thanks in advance.