Got the new 7290 a month ago from Cingular and upgraded it to 4.0.0.219. I can't put a call on hold, when I try, I get a pop-up box saying " ! operation failed". Tried resetting and reloading a JAVA file from tech support, no good.
I have no other issues.
Is there a patch?

this issue shouldn't be OS related, have you contacted Cingular to ensure that Call Holding has been provisioned to your service, with out the feature this error will result!