Help! DB2 CLP ERROR - DB21018E

Hi!

I need help with this error... When I execute 'db2' in unix prompt(Sun OS), it saw me this:

DB21018E A system error occurred. The command line processor could not
continue processing.

I couldn't execute any other db2 command... I read information about this error in "error messages" inside product support section, but it doesn't tell how to solve this problem.... I couldn't restart the machine so, i need to know how to "restart" db2 service or something like that.

Thanks...