Won't convert to .jpg on upload

For some reason I can't get .tif images (or any other) to convert to JPG format on upload...they stay in their original format.

Any idea? Here's my upload code

//Configure appearance.

iu.addParam("PaneLayout", "ThreePanes");

iu.addParam("FolderView", "Thumbnails");

iu.addParam("ShowDebugWindow", "true");

iu.addParam("BackgroundColor", "#eff1f9");

iu.addParam("ShowUploadListButtons", "true");

iu.addParam("ButtonRemoveFromUploadListText", "");

iu.addParam("ButtonRemoveAllFromUploadListText", "");

iu.addParam("UploadPaneBackgroundColor", "#ffffff");

iu.addParam("UploadPaneAllowRotate", "true");

iu.addParam("PaneBackgroundColor", "#ffffff");

iu.addParam("ShowDescriptions", "false");

iu.addParam("ShowButtons", "false");

//Hide standard upload pane.

iu.addParam("FolderPaneHeight", "-1");

//Configure upload parameters

iu.addParam("FilesPerOnePackageCount", "1"); //the number of files per package that are uploaded. -1 = all at once. positive integers equals allowed amount at once.

iu.addParam("AutoRecoverMaxTriesCount", "5"); //the number of times the uploader tries to upload due to a bad connection or other issue

iu.addParam("AutoRecoverTimeOut", "5000");

iu.addParam("MaxConnectionCount", "2"); //sets the number of concurrent uploads. Keep low. No higher than 3 or 4.

iu.addParam("FileMask", "*.jpg*;*.jpeg;*"); //only allow these filetypes to be uploaded to the server.

iu.addParam("AllowRotate", "true");

iu.addParam("UploadSourceFile", "true"); //upload the source image file.

iu.addParam("ExtractExif", "ExifXResolution");

iu.addParam("AdditionalFormName", "form_moredata");

iu.addParam("MaxFileCount", "100");

iu.addParam("MessageMaxFileCountExceededText", "You are limited to 50 items per upload.");

//Thumbnail 1 (medium)

iu.addParam("UploadThumbnail1FitMode", "Fit");

iu.addParam("UploadThumbnail1Width", "500");

iu.addParam("UploadThumbnail1Height", "500");

iu.addParam("UploadThumbnail1JpegQuality", "60");

iu.addParam("UploadThumbnail1CopyExif", "true");

iu.addParam("UploadThumbnail1CompressionMode", "*.jpeg,*.jpg,*.tif,*.bmp,*.wbmp,*.png=Jpeg;");

//Thumbnail 2 (thuumbs)

iu.addParam("UploadThumbnail2FitMode", "Fit");

iu.addParam("UploadThumbnail2Width", "200");

iu.addParam("UploadThumbnail2Height", "150");

iu.addParam("UploadThumbnail2JpegQuality", "45");

iu.addParam("UploadThumbnail2CopyExif", "true");

iu.addParam("UploadThumbnail2CompressionMode", "*.jpeg,*.jpg,*.tif,*.bmp,*.wbmp,*.png=Jpeg;");

//Thumbnail 2 (minis)

iu.addParam("UploadThumbnail3FitMode", "Fit");

iu.addParam("UploadThumbnail3Width", "75");

iu.addParam("UploadThumbnail3Height", "50");

iu.addParam("UploadThumbnail3JpegQuality", "15");

iu.addParam("UploadThumbnail3CompressionMode", "*.jpeg,*.jpg,*.tif,*.bmp,*.wbmp,*.png=Jpeg;");

OK, that'll allow for the uploading of the TIF files, but then how do I generate a thumbnail that is viewable in the browser? IE7 and 8 (I believe) do not support viewing of TIF files in a website like JPG and GIF images do. Is there no way to do that to support IE browsers? Does Firefox support TIF?