Dmitry - 2 thoughts, not sure you had a clear resolution to the problem yet...

1) We have seen this reproduced in the office when clients have a data pointer with a specific drive-letter path, possibly similar to your situation...
To test, our support staff downloads and runs the apps. Some testing machines did not have access to drive paths contained in the data.


Test machine a: points to i:\ub as a data folder, short-cut to launch application is a drive-letter path
Test machine a: does not have permissions for i:\ub folder, process being tested errors with 111

*-- similar error reproduced, not the letter E but another named cursor not specific to the code in operation...
Cannot update the cursor W55, since it is read-only.

Test machine b: has permission for the i:\ub folder
Test machine b: process being tested works fine

** note, there is no reference anywhere in the code to cursor with the name w55 **

This error has not happened often or recently and was corrected easily through permissions.
if you would need a sample of code that reproduces the error, let me know. I could probably come up with something for you,

2) we have seen a lack of anti-virus exclusions causing a host of permission-related issues. With the number of AV applications out in the world, it may be worth a look at this if the user is only able to reproduce the problem sporadically. Do you have a file exclusion recommendation for your software in place?

*-- un-resolved, sounds similar to your case
http://social.msdn.microsoft.com/Forums/en/visualfoxprogeneral/thread/3b882cea-9910-4222-acc2-92b2702eb064



>Hi,
>
>When attempting to preview a report a customer is getting error:
>
>

>Cannot update the cursor E, since it is read-only
>

>
>The E in the message does not have a colon; but could it be still pointing to a letter drive?
>
>TIA.