Robot busy error

Hi Experts,

I have been facing the " Robot busy, inventory operation in progress (254)" error from a quite long period.

we are using NB 6.0 ( Linux ) with NDMP.

Untill yesterday the restoration ran successfully. But when I started to restore some other data Its throwing Robot Busy error.

I restared media manager daemons, But no luck.

When I do robot inventory it taking long time but  gives no output, The prompt keeps waiting and there is pid for vmcheckxxx running backround.

Can you please let me know How can I overcome this issue and have a permanent fix.

Thanks in Advance..

Cheers

Albatorss