Too many entries in the phonebook

[gabkhorh]

Hi All, will like some advise from you.
Encountered an error recently with Alcatel PABX.
When trying to create an extension with name given, it gave me an error, "too many entries in the phonebook", "object -1 attribute 0".
No problem though if creating it without any name.
Also tested deleting an extension (with name) and recreated a new one (with name) but got the same error.
Any idea what is going on?