inetc plugin mangles URL and will not save file

[BoscoBilly]

Hello.
I am using the intec plugin to download a file on an amazon authenticated connection.
I am using an URL with a sig b64 hash, expire date and a couple of qry vars. It is URLencoded.
I create and pass the URL to inetc.
inetc, in 2 of 3 tries, receives an Access Forbidden or Bad Signature 403, in which case, no file is downloaded.
When it succeeds in getting the file, it "saves" an empty file.
I capture this url from the installer in debug by copy/paste from messagebox just b4 the get statement and when I type it in firefox or explorer, it works every time.
I am dependent upon this plugin and would much appreciate some help.
Thanks.

this is the simple 'get' I use:

inetc::get /CAPTION "Getting package...." /BANNER "Downloading files....." "$3" "$R7" /end
Pop $1
$3 is the URL and $R7 is the file to save to.