First check that you have the latest version(I think Version 1.2) and then, after downloading the latest, test the upload again. I'd be surprised if it was actually limited to 50K. If it still doesn't work then check the included source code, maybe the .ini, for a place to set that limit. I just did a check of Version 1.2 foxisapi .ini and .cpp in VFP 8 and couldn't find it though. Maybe you can set this in the .VFP. server?
The biggest problem I saw with uploading from FOXISAPI was when people pressed the STOP button on their browser in the middle of uploading. It causes the cpu on the web server to run and stay at 100%!!
Another free alternative that overcomes this upload problem is just to use the ASP Request.BinaryRead from within VFP and read chunks of data at a time. I have an example of this in ActiveVFP(http://www.activevfp.com/AVFPdemo2/default.asp?action=upload1 ). I think I set the limit in the example at 5MB but have tested with as much as 50mb. The uploads are incredibly fast and you can set the limit to whatever you want. It requires VFP7SP1 or higher if using the current version of AVFP although I also had it working in VFP6SP5 in previous versions.
>The foxisapi dll seems to be able to handle posting of 50K
>string maximum to the server. If this is correct does anyone know how
>to increase the size to say 10MB.