Thanks for the prompt response! (Top notch support is one of the things I mention when people ask me where we got our brilliant software from!).
Just out of interest (probably a long shot!), do you think something in the skins.ini/layout.ini file could cause this as you are unable to re-create the problem?
Chris.
Yup, speaking as someone who used to work in software support—it doesn’t get much better than Doktor Torben’s service! And not just Torben: many of us here in here are specialists in various aspects of mAirList. TonyW and Charlie are the layout-meisters, as well as knowing many scheduler programs. With my programming background (only about 36 years of it, in everything from assembler to APL (go look it up!) to COBOL to Visual BASIC, I can usually manage to create any mAirList scripts you can’t figure out yourself; and other utilities like my Excel template which will import MMD files so you can verify the contents easily, my no-install teleprompter, and such. And others can help with ‘now playing’ info for your website, connecting up your mixer’s ‘go’ buttons to mAirList, and lot and LOTS of other things!
Plus, we all have various levels of expertise in production, mixers, mikes, etc., etc. Oh, and in radio as well! ;D We’re quite the community in here, and we’re all eager to help out others whenever and however we can.
That’s a possibility. Do you have any ‘global’ progress bars set up, for example? Might be an idea to post a ZIPfile containing your mairlist.ini, skin.ini, layout.ini, and screenobjects.ini (if you use one). Then we can all have a neb and see if there’s anything ‘odd’ in them. 
BFN
CAD
Perfect! Thanks Torben.
I’ll post the skin/layout/mairlist ini files up when i get a chance tomorrow!
[quote=“Torben, post:20, topic:5443”]Looking at the call stack, the issue might in fact be related to the drawing of the progress bar. The hint that it happens only with “infinite” stream items was very helpful. It seems that the does not handle those streams correctly. Although I still haven’t been able to reproduce the problem, so it’s just a guess based on the reports you provided.
I have now modified the progress bar so that it is not drawn for those items, just a rectangle in the “idle” color (usually gray). Can you please try the snapshot I just uploaded (v2.2.1 b542). You just need to download and replace the mAirList.exe file, but in case it still doesn’t work, there’s also an update mAirList.map file in the download folder to generate a call stack.
http://www.mairlist.com/download/mAirList/v2.2/snapshot/[/quote]
Just to get this straight: You mean that the error disappeared now?
I don’t think it’s related to the skin or layout. The old drawing routine was requesting values (current playback position and duration) from an object which does not support this (infinite stream) and which return “random” values instead.
Logical, Doktor! 
I’d been puzzling over the concept of how a progress bar object would cope when instantiated for a (technically) infinite/null* length Item. Then I thought ‘Well, the progress bar must already cope with other zero/infinite/null* length Items such as DUMMY Items, for example … ?’
… and completely forgetting that those types of Items don’t actually ever get loaded into Player objects. :-[
S – I – G – H! <
BFN
CAD
Funnily enough, the IAudioSource object playing an infinite stream item does report a position, that is, the number of seconds played so far. But it does not report a duration, but 0. I guess this is what was confusing the progress bar.