Hi Tim;
Sorry for the memory switch digression but the thought there was that maybe your Blob size limitation (way before the 2G limit) was because your PB Application was running out of usable memory when running as a 32 bit application. Especially, since you mentioned "threads" - so I assume that you are running a multi-threaded application.
If that is truly the case and you are running up against the 2G application memory space limitation then the following things might help you work around this issue:
1) You can try either mechanism that Bruce or I mentioned to raise the usable memory to 3G - but, in my experience doing this, many applications can become really unstable when running in this mode. However, it might be worth a try and see what happens in your case.
2) You could consider upgrading to PB 12.6 where Classic application .EXE's can now be compiled to 64bits.
3) The key with my applications is that I release large storage ASAP. In the case of your application using Blobs, I would code the following (if you already haven't) ... for example:
Blob lblb_null
Blob lblb_data
Long ll_len
SetNull (lblb_null)
ll_len = FileReadEx (li_FileNo, lblb_data)
<blob processing>
lblb_data = lblb_null
4) Make sure that you destroy any Classes ASAP that you no longer need.
5) Never use Auto Instantiated Classes as do not release their memory until the application is closing.
6) Try using the GarbageCollect ( ) commands after each processing loop
7) Always clean-up your DW Controls or DS's as follows to also release DWO's memory.
DS.Reset ()
DS.DataObject = ""
Destroy DS
HTH
Regards ... Chris