I'm having this problem, too. Image uploader stopped working. I checked #3 on the checklist, but my site alias default looks right.
Out of curiosity, I went to look at Variant Images and got this error:
An unexpected error has occurred! DotNetNuke.Services.Exceptions.ModuleLoadException: Index was outside the bounds of the array. ---> System.IndexOutOfRangeException: Index was outside the bounds of the array. at CartViper.Modules.Store.Catalog.ProductVariantInventoryInfo.TraverseVariants(IList`1 variants, Int32 productId) at CartViper.Modules.Store.WebControls.ProductVariantImagesAdmin.gvVariantImages_ItemDataBound(Object sender, DataGridItemEventArgs e) at System.Web.UI.WebControls.DataGrid.CreateItem(Int32 itemIndex, Int32 dataSourceIndex, ListItemType itemType, Boolean dataBind, Object dataItem, DataGridColumn[] columns, TableRowCollection rows, PagedDataSource pagedDataSource) at System.Web.UI.WebControls.DataGrid.CreateControlHierarchy(Boolean useDataSource) at System.Web.UI.WebControls.BaseDataList.OnDataBinding(EventArgs e) at CartViper.Modules.Store.WebControls.ProductVariantImagesAdmin.Page_Load(Object sender, EventArgs e) at CartViper.Modules.Store.Components.StoreControlBase.OnLoad(EventArgs e) --- End of inner exception stack trace ---
ETA: Incidentally, I have two separate DNN installs, both running the same version of DNN and CartViper. The image uploader is working on one but not the other.