This study analyzes acquired dysgraphia observed in a French-speaking woman. The results point to an impairment of the graphemic buffer, i.e., the processing stage where abstract orthographic representations are temporarily stored while planning the written production. However, the spelling errors were more frequent in the irregular than in the regular words. A qualitative analysis of the errors in the irregular misspelled words showed that, in general, these were not "regularization" errors, but rather the same characteristics as the phonologically implausible errors found in the regular words, such as letters substitutions, deletions, additions, and transpositions. Furthermore, in a list of regular and irregular words of same length and graphemic structure, the errors not only tended to concentrate on the irregularity itself but also tended to be more frequent elsewhere in the irregular words compared to the regular words. These finding are discussed in terms of a post-lexical sensitivity to irregular spelling. It is also shown that when focusing attention on the irregularity becomes necessary, this can cause a detriment to the surrounding graphemic constituents. Interaction between attentional resources and processing of orthographic representations at the graphemic buffer level is considered.