Yes. I knew it.
That is the problem. I used Report generation toolkit with LV 6.0 and everything was fine. Then I've got LV 6.1 and when I recompiled my sub vi's into LV 6.1 i started experience all that strange problems. I contacted several times with NI, and they could not explain what is going on. I gave them my program and they worked fine on their machines.
So what I did to solve this problem:
Unistall report generation toolkit through Control Panel >> Add/Remove software.
Install (if you have) old report generation toolkit for LV 6.0.
I checked your VI on my computer - it works fine.
Something is wrong with new Report generation toolkit for LV 6.1
Yesterday I followed another guy who experienced the same problem. So you are not alone:)
If you don't have old version of report generation toolkit, contact NI tech support and ask them to give it to you.
Have a good luck, and reply if you have any success.
Peter