'Rename files' step fails

[teognost]

I tried some workaround-introduced a Wait step for 10 sec-between the step producing addedResults.xml and the step renaming addedResults.xml.This seems to solve the issue but I do not understand exactly why.
But now I begin to have other issues-I have a step setting File version for a C# solution,from this morning it fails:

Error firing vbld_StepDone event: Error in Step (VBScript) script code at Line 32, Column 1 (Permission denied)

where the line failing is;
Set file=vbld_FSO().OpenTextFile(strCurrProjLogFullPat h,ForAppending,TRUE)

I just open a file in order to write inside the content of LASTSTEP_OUTPUT.

Previous step is writing into this file as well.

I suspect this error is somehow related with the previous one with 'Rename Files'.It is like something happened yesterday on the build box so from that moment a VBP step would keep a file locked more than normal so next step would find the file locked and it would fail.But you wrote this is not possible so I really have no real clue about what is going on :-(