Hi,
I don't know which version of Informix you are using. Also I donot know about the type of stored procedure
If this is a Java procedure [udr], then it is a bug. Try installing patch. The problem is with the memory.
If this is the case then talk to informix tech-support.
Otherwise, if this is a ordinary procedure, then try optimizing the sql that you are using as GRP said above.
Hope this makes some sense.
Regards
Partha