I have a similar EAccessViolation error.
Upon double clicking the iso file, the following message appears:
Message: Access violation at address 004F9AF4 in module 'UltraISO.exe'. Read of address 70C23740
If I try to open the iso file from inside UltraISO, I get the error in class TToolbar.
The particular iso file was created with ImgBurn, using UDF v2.01. Previously, I used to use UDF v1.50 and I had no problems.
I can mount and burn the iso just fine, using other programs.
In fact, any iso created with UDF v2.01 can't be opened by UltraISO. I haven't tried other versions, though.
Edited by Cube8 on Aug. 22 2012,18:55