Rendering to disk won't create a proper .asd file

[drumspyder]

(Note: I'm new to the forum so excuse me if this topic has been covered)
Using Live 6.03 (and previous versions of 6) I render files to disk with the "create .asd" + "render as a loop" options checked, but when I open the resulting clip it shows up as either an unwarped sample or with default (and often incorrect) warp markers. In other words Live acts as though the sample has no asd file. By the way, before I open the newly rendered clip, the browser shows it with that checkmark beside it, so maybe Live is creating an asd file which is corrrupt or dysfunctional in some way.
Anyone else had this problem or is there something I've overlooked?
Thanks
Scott