I can open files using the File/Open menu OK unless I’ve been using a flash memory card. Then I get a "No Disk" error dialog. This happens after I’ve removed the memory card even if I didn’t use Multi-Edit while the card was inserted. On the error dialog, I can click Cancel and then I will get the usual Edit New File dialog. The problem persists until I reboot.
As an additional annoyance, the Edit New File dialog appears under the Multi-Edit window where it is hard to find.
Is there anyway to stop Multi-Edit from trying to access the non-existent drive?
While the no disk issue sounds like an Operating system issue, you could try changing to a different file prompt to see if that clears it up. Go to Tools-Customize-Files, then under File prompt, check or uncheck "Use Explorer style" you may also want to uncheck "Use path from last file" and see if either of those helps.
Since switching to Win 7 I have noticed a buried file open or file save dialog with a number of older apps. You might try dragging the dialog so that it is completely over the application window before pressing the OK button. That may help.