Invisible Window

This is a really strange issue and I haven't been able to find any information on it.

I have an interactive RPG IV program (not ILE), and within it I have my "Are You Sure" window. When someone wants to delete a record (by pressing F22) I pop up the window and make them press "Y" and Enter to do the delete. This works fine most of the time but occasionally (once or twice a week) when the user presses F22 their session goes into Input Inhibited status and just sits there, hung. I check their job and the iSeries says they are sitting at the "Are You Sure" window, and it's waiting for a response from them. The user sees no window on their display and AFATK, they're waiting on the system to pop up the window. This is happening to multiple users, in multiple programs. They are using HP & Neoware thin clients, although so far it seems to be happening only to the Neoware users (not sure about that). If I have the user press Sys-Req or ATTN, it gives them an I/O error.

Here is the DDS for the window:

A R SUREYN
A*%%TS SD 20100318 140808 TADAIR REL-V6R1M0 5761-WDS
A WINDOW(*DFT 10 37)
A OVERLAY
A WDWBORDER((*COLOR GRN) (*DSPATR RI)-
A (*CHAR '...:::.:'))
A 2 10'Confirmation Window'
A DSPATR(HI)
A DSPATR(UL)
A SURTX1 35A O 4 2
A SURTX2 35A O 5 2
A SURTX3 35A O 6 2
A 8 8'Are you sure? (Y/N):'
A DSPATR(HI)
A SURE 1A B 8 29CHECK(ME)
A VALUES('Y' 'N')
A CHECK(MF)
A DFTVAL('N')



Here is the call:

if DeleteRec;
clear SureYN;
surtx1 = ' You are about to ';
surtx2 = ' delete this order. ';
surtx3 = ' ';
exsr AreYouSure;
if Sure <> 'Y';
DeleteRec = *off;
iter;
endif;
exsr delet;
BackToSFL = *on;
exsr rels;
leave;
endif;




Here is the subroutine:

begsr AreYouSure;
clear Sure;
exfmt SureYN;
if Cancel;
Sure = 'N';
endif;
endsr;




Any ideas? I'm almost ready to attribute this to gremlins. (Don't get them wet. Don't feed them after midnight. Etc.)