With 10.1, all the new functionality are made to use the filename same as number and the "check in all-in-one catpart" is different. it creates a CATPart called "product-name_AllCATPart.CATPart". If you have customization to rename cad document after check in to change the filename to "number.CATPart". This function is not able to find the older iteration. Please use the category, sub-category and link (source and image, contributing image) to identify the older iteration of the all-in-one CATPart.