How do I uncheck 'greyed out' revisions on sheet?

[TEF]

Help! Need to issue dwgs today - eek!

Using 2010 and my sheet contains revisions I want to get remove from the titleblcok.

But when I go to my sheet and 'view properties' and edit 'revision on sheet' some of my issues are greyed out so I cannot uncheck and remove them.

How do I sort this out and uncheck the greyed out box?

Under my view tab and sheet composition 'sheet issues/revisison' area I have numbering per sheet and none of my 'issued' check boxed are ticked. Any tips?

[TEF]

ok all good. just figured out a work around, just removed all information relating to that issue from the sheet composition area (as that wasn't greyed out) and now it shows up as a blank item on my titleblock. Still greyed out for some reason on my sheets view properties, but that doesn't matter now as the revsion info has all been deleted.