HashMap problem

[Dalibor Dostál]

Hello all,
I need help with following problem: when invoking remote axis web 
service with Hashmap argument, from time to time it doesn´t succeed
on remote side with this message

java.lang.IllegalArgumentException: object is not an instance of 
declaring class
20041013 15:07:23 [S]VFRA: Tried to invoke method public 
java.util.HashMap WebSluzbyFlat.zpracujPozadavek(java.util.HashMap) with 
arguments java.util.HashMap.
The arguments do not match the signature.; nested exception is:
java.lang.IllegalArgumentException: object is not an instance of 
declaring class

We are using java 1.3.1 and axis 1.2RC1 on AIX 4.3.3.
Thanks in advance
Dalibor Dostál