System Error: &H8001010D (-2147417843) An outgoing call cannot be executed...

[PaxMundi]

Hi everybody,
This is my first post here, and I hope to find a solution to the above error message.
I've developed an EXCEL-VBA application (originally in MS Office 2007 Professional SP2). It executes smoothly in XP and Vista.
The application uses the MSCAL.OCX (calendar control 12.0, which is part of ACCESS 2007).
When trying to install the software on another PC (VISTA Office 2007 without Access and without MSCAL.OCX - I had to copy the file and register it via regsvr32.
After that, the application runs also on that configuration.


However, the problem arose when I had to install my software on another PC (Windows7 & Office 2010), since Microsoft removed MSCAL.OCX from Office 2010. The following is aquotation from microsoft:
"Calendar control
Calendar control (mscal.ocx) was a Microsoft Access feature that could be used in Access worksheets. Calendar control is removed in Access 2010 and is not usable for Excel 2010."


I did manage to install the calendar control 12.0 on that machine, but since then my application encounters the following error every once in a while:


System Error &H8001010D (-2147417843)
An outgoing call cannot be executed because the application is
forwarding an input-synchronized call.


Well, after this long prelude I have two questions:

1. Is MSCAL.OCX the "culprit" for the error in the program?

2. If it is, what can be done to bypass this error? what is the best alternative?

[PaxMundi]

I've installed today another version of the program (this time, without MSCAL.OCX) on the "culprit" PC, but the problem recurs (which proves that it has nothing to do with the calendar).


The program's behaviour is quite bizarre: It executes smoothly exactly twice (!!!) and then fails to execute again, displaying an error message. In order to run the program again, one has to exit EXCEL altogether and then re-run the program (either via an icon configured in the QAT = Quick Access Toolbar) or by opening the workbook "hosting" the program and clicking on a button, which executes the macro).


While in debug mode, I put the debug.print error.number statement before and after the first statement in the code (Form.show vbmodal) and it seems that the error is generated while trying to execute this very statement (i.e. Form.show): I get the 21472221232 error number in the immediate window (see attached image).


Some "googling" produced the following result:
Automation Error &H80040110 (-2147221232) Class does not support aggregation (or class object is remote).

I would appreciate it very much if someone could explain what causes the problem and how it should be resolved.