Blocked Download Accelerator Software?

[Razmoudah]

I hope this is in the right place, but I'd just found out about the Long War mod for XCOM and registered to download it. When I clicked on the link there was a pop-up saying that you block download accelerator software and plug-ins, but I use one for all of my downloads and it took it over, and did a multi-thread download, without any problems. Was that supposed to work just fine or not? Going by the pop-up it wasn't, and I thought you guys might want to know. The download manager software I use is Internet Download Manager, and the browser I use is Firefox.