I have a POS application which works well for a time, but then without warning the screen disappears! The screen has a menu for the user which is a 5x8 screen of buttons, and each button is made of a container of 5 separate objects - this is so that I can allow the user to uniquely define the menu (text, pictures [we do not allow .ICO files since they have been identified as a potential for memory leaks], background and foreground color).

The problem seems to occur when I bring up a modal window on top of the POS screen (ie a window to allow the user to change a price). When the modal window is closed, the entire POS screen goes away, as if the thisform.Release() has been called. While this behavior is reproducible, it is very sporadic.

Please note that after every transaction I issue a CLEAR RESOURCES command to clear the memory, but I still get the error.

Also, initially the POS application was designed to appear as a top level form. In trying to resolve this problem, we changed the ShowWindow property to be "In Top-level form", but that hasn't helped either.

I am using VFP 7.0 SP1 on my W2K development machine (PIII 450mhz, 256mb RAM) and am unable to replicate the problem. But I am able to replicate the problem on my test machine (P166mhz, 64mb RAM). Prior to updating to SP1, having the screen disappear would often happen as soon as a modal window is called, but when the POS app is restarted, I would no longer get the error when calling the same modal window.

We have customers who are seeing it frequently. The clients are running a variety of machines with OS's including Win95, 98 , Me, NT4, and 2000), and processors ranging from PII 266mhz to P4 1.2ghz, and RAM ranging from 64mb to 128mb. The error is occurring less frequently if the client shuts down and restarts the workstation the start of the day and also less frequently when there is more memory.

If the problem is a memory leak, what is the best way to find out where the leak is occurring, and what is the best way to fix it?

Any help or suggestions on what to look for is greatly appreciated!

Carsten Thode
Carsten.Thode@fox-industries.com